Ung_dung_etab_trong_tinh_toan_cong_trinh

8/7/2019 Ung_dung_etab_trong_tinh_toan_cong_trinh

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1

Paris, 25/11/2008

KS.GV.THS.Tr n Anh B nh

Sinh ngy 03/10/1981 Nam nh

Gi ng vin :

B Mn Tin Hc Xy Dng, Khoa Cng Ngh ThngTin, trng i Hc Xy Dng. a ch : s 55ng Gii Phng, H Ni, www.nuce.edu.vn

Doctorant EDF/ Universit Paris-Est :

EDF R&D, Dpartement MMC, Site des Renardires.Adresse : Avenue des Renardires Ecuelles, F-77818 Moret sur Loing cdex, France, www.edf.fr

Universit Paris-Est, Laboratoire MSME, FRE 3160CNRS. Adresse : 5, Boulevard Descartes, 77454Marne la Valle Cedex 2, France, www.univ-mlv.fr

Ti li u khng trnh khi nhng thiu st. S gp ca c gi s gp thm phn hon thi n cho ti liu ny. Mi gp xin gi v a ch sau, tc gi xin chn thnh cm n !

in thoi: 0033.6.18.93.03.94 .

Email : [email protected]
http://www.nuce.edu.vn/http://www.nuce.edu.vn/http://www.nuce.edu.vn/http://www.edf.fr/http://www.edf.fr/http://www.edf.fr/http://www.univ-mlv.fr/http://www.univ-mlv.fr/http://www.univ-mlv.fr/mailto:[email protected]:[email protected]:[email protected]:[email protected]://www.univ-mlv.fr/http://www.edf.fr/http://www.nuce.edu.vn/


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ng dng ETABS trong tnh ton cng trnh2

NG DNG ETABS TRONG TNHTON CNG TRNH

Bn tho ko in c

Tng b m gi v iTng v hinyu qu

Tng con trai ngoan d u yu

Chn thnh c m n cng ty t vn xy dng CDC, b mn Tin Hc Xy Dng Khoa Cng Ngh Thng Tin Trng i Hc Xy Dng H Ni gip ti hon thnh ti liu ny.


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ng dng ETABS trong tnh ton cng trnh 3

Ch ng 1: Tng Quan v Etabs

............................... 121. H ta

................................................................................................................. 12

2. Nt

........................................................................................................................... 12

2.1. Tng quan v nt (Joint)

................................................................................... 12

2.2. H ta a ph ng

........................................................................................ 13

2.3. Bc t do ti nt

................................................................................................ 13

2.4. Ti trng ti nt

................................................................................................. 14

2.5. Khi l ng ti nt (Mass) ................................................................................... 143. Cc loi lin kt

....................................................................................................... 15

3.1. Retraints

........................................................................................................... 15

3.1.1. Khi nim chung

......................................................................................... 15

3.1.2.Ph ng php gn

....................................................................................... 16

3.2. Springs

.............................................................................................................. 16


......................................................................................... 16

3.2.2. Ph ng php khai bo lin kt Spring

......................................................... 16

3.3. Lin kt Constraints

.......................................................................................... 17


......................................................................................... 17

3.3.2. Cch khai bo

............................................................................................. 17

3.3.3. ng dng

.................................................................................................... 17

4. Vt liu

.................................................................................................................... 18

4.1. Tng quan v vt liu

........................................................................................ 18

4.2. H trc ta a ph ng

................................................................................. 19

4.3. ng sut v bin dng ca vt liu (stresses and strains)

................................. 19

4.3.1. Stress

......................................................................................................... 19

4.3.2. Strain

.......................................................................................................... 19

4.4. Cc thng s khai bo vt liu

.......................................................................... 20

5. Ti trng v t hp ti trng

..................................................................................... 21


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5.1. Ti trng

............................................................................................................ 21

5.2. T hp ti trng ................................................................................................. 225.2.1. Cc cch t hp ti trng

............................................................................ 22

5.2.2. Cc loi t hp ti trng

.............................................................................. 22

5.2.3. Cch khai bo

............................................................................................. 23

6. Bi ton phn tch

.................................................................................................... 23

6.1. Cc dng phn tch kt cu

............................................................................... 23

6.2. Modal Analysis

.................................................................................................. 23

6.2.1. Tng quan

.................................................................................................. 23

6.2.2. Eigenvertor Analysis

................................................................................... 24

7. Diaphragm Centers of Rigidity, Centers of Mass

..................................................... 25

Ch ng 2: Kt cu h thanh

.................................... 281. Tng quan v phn t thanh

.................................................................................... 28

1.1. Phn t thanh (Frame Element) ........................................................................ 281.1.1. Khi nim

................................................................................................... 28

1.1.2. ng dng

.................................................................................................... 28

1.2. H trc ta a ph ng (Local Coordinate System)

...................................... 28

1.2.1. Khi nim

................................................................................................... 28

1.2.2. Mc nh

..................................................................................................... 28

1.2.3. Hiu chnh

.................................................................................................. 29

1.3. Bc t do (Degree of Freedom) ......................................................................... 301.4. Khi l ng (Mass)

............................................................................................. 30

2. Tit din (Frame Section)

........................................................................................ 30

2.1. Khai bo tit din

.............................................................................................. 30

2.2. Thanh c tit din thay i (Non-Prismatic Sections)

........................................ 31

2.3. Tit din khng c hnh dng xc nh (General)

.............................................. 32


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2.4. Thay i thng s tit din

................................................................................ 33

2.4.1. Thng s hnh hc v c hc ca tit din .................................................. 332.4.2. Thay i cc thng s hnh hc v c hc

.................................................. 35

3. Lin kt gia hai phn t

.......................................................................................... 36

3.1. im chn (Insertion point)

............................................................................... 36

3.1.1. Khi nim

................................................................................................... 36

3.1.2. Ph ng php khai bo

................................................................................ 37

3.2. im giao (End offsets)

..................................................................................... 39

3.2.1. Khi nim

................................................................................................... 39

3.2.2.Ph ng php khai b o

................................................................................ 39

3.3. Linkt Release (Frame Releases and Partial Fixity)

....................................... 40

3.3.1. Khi nim

................................................................................................... 40

3.3.2.Ph ng php khai bo

................................................................................ 41

4. T ng chia nh phn t (Automatic Frame Subdivide)

.......................................... 41

4.1. Khi nim

.......................................................................................................... 41

4.2. Ph ng php khai bo

...................................................................................... 41

Ch ng 3: Kt cu tm v

........................................ 44

1. Phn t Tm bn

..................................................................................................... 44

1.1. Phn t Area (Area Element)

............................................................................ 44


......................................................................................... 44

1.1.2. Thickness Formulation (Thick Thin) ......................................................... 441.1.3. Thickness

................................................................................................... 45

1.1.4. Material Angle

............................................................................................. 45


...................................... 46

1.2.1. Trng thimc nh

.................................................................................... 46

1.2.2. Bin i

...................................................................................................... 47


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1.3. Tit din

............................................................................................................ 48

1.4. Bc t do (Degree of Freedom) ......................................................................... 481.5. Mass

................................................................................................................. 49

1.6. Ni lc v ng sut

............................................................................................ 49

1.6.1. Ni lc

........................................................................................................ 49

1.6.2. ng sut

..................................................................................................... 51

2. Vch cng

............................................................................................................... 52

2.1. Tng quan v Pier v Spendrel

......................................................................... 52

2.1.1. Khi nim

................................................................................................... 52

2.1.2. t tn phn t

........................................................................................... 52


................................................................................. 53

2.2.1. Phn t Pier

................................................................................................ 53

2.2.2. Phn t Spandrel

........................................................................................ 53

2.2.3. Hin th h ta a ph ng

..................................................................... 54

2.3. Tit din

............................................................................................................ 54

2.3.1. t tn phn t Pier v Spandrel

................................................................ 55

2.3.2. nh ngha tit din Pier

.............................................................................. 56

2.3.3. Gn tit din Pier

........................................................................................ 57

2.4. Ni lc phn t Pier v Spandrel

....................................................................... 57

2.5. Kt qu thit k vch

......................................................................................... 58

2.5.1. Pier result Design

....................................................................................... 58

2.5.2. Spandrel Result Design .............................................................................. 583. Chia nh phn t (Area Mesh Options)

.................................................................... 58

3.1. Khi nim

.......................................................................................................... 58

3.2. Ph ng php chia nh

...................................................................................... 59

Ch ng 4: Ph lc

....................................................... 62


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1. Section Designer

..................................................................................................... 62

1.1. Tng quan ......................................................................................................... 621.2. Cn bn v Section Designer

............................................................................ 62

1.2.1. Khi ng Section Designer

....................................................................... 62

1.2.2. Hp thoi Pier Section Data

........................................................................ 63

1.2.3. Hp thoi SD Section Data

......................................................................... 64

1.3. Ch ng trnh Section Designer

.......................................................................... 65

1.3.1. Giao din ch ng trnh Section Designer

.................................................... 65

1.3.2. H trc ta

............................................................................................. 65

1.3.3. Tit din v hnh dng (Sections and Shapes)

............................................ 66

1.3.4. Ct thp gia c ng

...................................................................................... 67

1.3.5. Ph ng php v

......................................................................................... 69

1.4. Section Properties

............................................................................................. 69

1.4.1. Mc ch ca Section Properties

................................................................. 69

1.4.2. Thng s thit din

..................................................................................... 69

1.5. V d

.................................................................................................................. 70

2. L i (Grid)

............................................................................................................... 73

2.1. Hp thoi Building Plan Grid System and Story Data Definition

........................ 73

2.2. Hp thoi Grid Labeling Options

....................................................................... 74

2.3. Hp thoi Define Grid Data

............................................................................... 75

2.4. Hp thoi Story Data

......................................................................................... 76

2.5. Cc ch v ................................................................................................... 773. Ti trng (Load)

....................................................................................................... 78

3.1. Wind Load

......................................................................................................... 78

3.2. Quake Lad

........................................................................................................ 79

4. cc ph ng php chn phn t

................................................................................ 81

4.1. Chn phn t trn mt bng

.............................................................................. 81

4.2. a im nhn ra v cng

................................................................................. 82


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4.3. S dng thanh cng c

..................................................................................... 82

4.4. S dng chc nng trong menu Select .............................................................. 825. Hp thoi Replicate

................................................................................................. 83

Ch ng 5: Bi tp thc hnh

................................... 861. Bi tp 1

.................................................................................................................. 86

1.1. Lp h l i.

....................................................................................................... 86

1.2. Khai bo cc c tr ng hnh hc v vt liu:

..................................................... 92

1.3. V s kt cu.

.............................................................................................. 97

1.3.1. Vmt bng dm

....................................................................................... 98

1.3.2. V mt bng ct.

...................................................................................... 103

1.3.3. V mt bng sn

...................................................................................... 104

1.4. Sao chp mt bng kt cu

............................................................................. 105

1.5. Gn lin kt ni t.

........................................................................................ 107

1.6. Ph ng php v sn nh ra ............................................................................ 1071.7. Gn sn tuyt i cng

................................................................................... 108

1.7.1. nh ngha cc Diaphragms

...................................................................... 108

1.7.2. Gn Diaphragms cho cc tng

.................................................................. 108

1.8. nh ngha cc tr ng hp ti trng

................................................................. 108

1.9. Khai bo khi l ng ca cng trnh

.................................................................. 109

1.10. Khai bo t ng chia nh sn v dm

......................................................... 109

1.10.1. T ng chia nh dm ............................................................................ 1091.10.2. T ng chia nh sn

............................................................................. 109

1.11. Kim tra m hnh

........................................................................................... 110

1.11.1. V d 1

.................................................................................................... 111

1.11.2. V d 2

.................................................................................................... 111

1.11.3. V d 3

.................................................................................................... 112


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1.11.4. V d 4

.................................................................................................... 112

1.12. Chy m hnh ................................................................................................ 1121.13. Ta tm cng v tm khi l ng tn s dao ng

.................................... 112

1.14. Phng ph p nhp ti vo tm khi l ng

.................................................. 113

1.15. Nhp ti trng vo tm cng

......................................................................... 115

1.16. T hp ti trng

............................................................................................. 116

1.17. Kim tra li s kt cu

.............................................................................. 117

1.17.1. Kim tra li s hnh hc

...................................................................... 117

1.17.2. Kim tra li s titrng

...................................................................... 117

1.18. Chy ch ng trnh v quan st ni lc

........................................................... 118

1.19. Khai bo bi ton thit k ct thp cho Frame

............................................... 119

2. Bi tp 2

................................................................................................................ 122

2.1. Thit lp h l i

............................................................................................... 123

2.2. nh ngha tit din v vtliu

......................................................................... 125

2.2.1. nh ngha vt liu

.................................................................................... 125

2.2.2. Khai bo tit din

...................................................................................... 126

2.3. V s kt cu

............................................................................................. 126

2.4. To lp h ta tr

....................................................................................... 131

2.5. nh ngha cc tr ng hp ti trng

................................................................. 134

2.6. Khai bo t hp ti trng

................................................................................. 134

2.7. Nhp ti trng

................................................................................................. 135

2.7.1. Tnh ti ...................................................................................................... 1352.7.2. Hot ti

..................................................................................................... 135

2.7.3. Ti trng gi theo ph ng Y

...................................................................... 136

2.8. Khaibo t ng chia nh sn v dm

........................................................... 136

2.9. Hp nht cc im qu gn nhau

.................................................................... 137

2.10. Kim tra m hnh

........................................................................................... 137

2.11. t tn vch

.................................................................................................. 137


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2.11.1. t tn cho Pier

...................................................................................... 137

2.11.2. t tn cho Spandrel .............................................................................. 1372.12. nh ngha tit din vch

............................................................................... 138

2.13. Gn tit din vch

......................................................................................... 139

2.14. Khai bo tiu chun thit k vch

.................................................................. 139

2.15. Thc hin bi ton kim tra vch

................................................................... 139

2.16. c kt qu tnh ton

.................................................................................... 139

2.17. Ph lc

.......................................................................................................... 140

2.17.1. Nng nh ln 8 tng

............................................................................... 140

2.17.2. To mt ct zic zc

................................................................................. 142

3. Bi tp 3

................................................................................................................ 145

3.1. Lp mt bng kt cu trong AutoCAD

............................................................. 145

3.1.1. To cc layer

............................................................................................ 145

3.1.2. V mt bng dm

..................................................................................... 145

3.1.3. V mt bng l i.

...................................................................................... 146

3.1.4. V mt bng ct

....................................................................................... 146

3.1.5. V mt bng vch

..................................................................................... 147

3.1.6. Xut mt bng kt cu ra file mi

.............................................................. 148

3.2. Nhp m hnh t AutoCAD v Etabs

............................................................... 149

3.2.1. Nhp mt bng l i

................................................................................... 149

3.2.2. nh ngha tit din, vt liu

...................................................................... 152

3.2.3. Nhp mt bng dm ct ............................................................................ 1523.2.4. Nhp mt bng vch v v vch

............................................................... 153

4. Bi tp 4

................................................................................................................ 156

4.1. Thit lp h l i

............................................................................................... 157

4.2. nh ngha tit din v vtliu

......................................................................... 159

4.2.1. nh ngha vt liu

.................................................................................... 159

4.2.2. Khai bo tit din

...................................................................................... 159


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4.3. V m hnh

...................................................................................................... 167

4.3.1. V mt ct qua trc 1 ................................................................................ 1674.3.2. Hiu chnh li ct d i

............................................................................... 171

4.3.3. V dm cu trc

....................................................................................... 173

4.3.4. V cc thanh ging ngang

........................................................................ 175


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Ch ng 1: Tng Quan v Etabs 12

Ch ng 1: Tng Quan v Etabs

1. H ta Trong Etabs cng nh trong Sap2000, chng ta c hai h trc ta Decard v tr:

Hnh 1. 1 H ta Decard. Hnh 1. 1 H ta tr.

Ph ng php s dng hai h ta Tr v Decard c cp c th trong bi tp s 1.

2. Nt2.1. Tng quan v nt (Joint)C th hiu ntl im lin kt cc phn t; l im ti ta gn chuyn v c ng bchoc gn cc iu kin bin; l im xc nh iu kin bin; l im cn gn lc tptrung; l im gn khi l ng tp trung.

Ttc ti trng (load ) v khi l ng (mass ) gn cho phn t c quy i v cc titrng tp trung, khi l ng tp trung ti cc nt.

Cc cch to ra nt :

Cc nt c to t ng khi to phn t.

Ngoi ra ta c thm nt ti bt k v tr no.


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Ch ng 1: Tng Quan v Etabs14

Hnh 1. 4 Hp thoi Point Forces.

Hnh 1. 5 Vector m men.

2.4. Ti trng ti nt

Ti nt c cc ti trng tp trung (concentrated forces ) bao gm mmen v lc. Ngoi racn c cc chuyn v c ng bc ti nt.

Ph ng php nhp ti trng tp trung ti nt:

Chn nt cn gn ti trng.

Vo MenuAssign Joint/Point Loads Force .

+ Force Global X, Y, Z : lc tc dng vont theo ph ng v chiu ca cc trcta tng th X, Y, Z.

+ Moment Global XX, YY, ZZ : vector moment tc dng vo nt theo ph ngv chiu ca cc trc ta tngth X, Y, Z.

Gii thch v Vector m men.

+ Ti im c s hiu (Label ) l 5, cMzz =10. C ngha l chiu cavector moment ng c vi chiud ng ca trc Z. Nh vy vi tcdng ca ti trng nh trn, thanh5-6 s b un trong mt phngsong song vi mt phng XY,chiu un t Y sang X(hnh 1. 5).

2.5. Khi l ng ti nt (Mass) Trong cc bi ton phn tch ng (Dynamic Analysis), khi l ng ca kt cu c dng

tnh lc qun tnh v tn s dao ng ring ca cng trnh. Thng th ng, ch ng trnhs tnh khi l ng ca cc phn t da trn khai bo khi l ng ring ca vt liu v thtch hnh hc ca phn t, sau ch ng trnh s quy i v nt. Khi l ng ca tngphn t s c tnh cho 3 ph ng t ng ng vi 3 chuyn v thng ca nt. Ch ng trnhs b qua m men qun tnh.

Trong mt s tr ng hp, khi tnh ton dao ng ca cng trnh, ta khng dng khi l ngm Etabs t tnh. Khi , ta c th khai bo khi l ng tp trung hoc khi l ng m menqun tnh tp trungti bt k nt no. Ph ng php khai bo khi l ng tp trung nh sau:


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Hnh 1. 6 Hp thoiAssi n Masses.

Chn nt cn gn thm ti trng tp trung.

Vo MenuAsign Joint/Point Additional Point Mass (hnh 1.6).

Direction X, Y, Z : khi l ng tp trung ti nt theo baph ng X, Y, Z trong h ta tng th.

Rotation about X, Y, Z : khi l n g m men qun tnhtp trung ti nt theo ba ph ng X, Y, Z trong h ta tng th.

3. Cc loi lin kt3.1. Retraints

3.1.1. Khi nim chungNu chuyn v ca mt im theo mt ph ng no c c nh tr c, ta ni im b rng buc lin ktRestraint. Gi tr chuyn v ti im c th bng khng hoc khc khng, ty thuc vont c chu chuyn v c ng bc hay khng.

Nt c lin kt Restraint s c phn lc. Gi tr phn lc ny s c xc nh trong bi

ton phn tch kt cu(Analyse).Lin kt Restraint th ng c m hnh ha cc kiu lin kt ni t ca kt cu.

Hnh 1. 7 Cc loi lin kt ni t


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Hnh 1. 8 Hp thoi AssignRestraints.

Hnh 1. 9 Hp thoiAssign Springs.

3.1.2. Ph ng php gn

Ph ng php gn lin kt Restraint: Chn im cn gn lin kt Restraint.

Vo menu Assign Joint/Point Restraints(Supports) .

Nhpcc bc t do b khng ch vohp thoi.

+ Translation : chuyn v thng.

+ Rotation: chuyn v xoay.

3.2. Springs3.2.1. Khi nim chungSpring l lin kt n hi. Bt k mt trong su bc t doca mt nt u c th gn lin kt n hi. Lin kt nhi c m hnh ha bng cc l so. cng ca linkt n hi chnh l cng ca l so. Lin kt n hi cth bao gm chuyn v c ng bc.

im c lin kt n hi s c phn lc n hi. ln

ca phn lc ph thuc vo cng ca lin kt v c xc nh trong bi ton phn tchkt cu.

Lin kt Spring th ng c s dng trong cc bi ton:

Dm trn nn n hi (mng bng).

Tm trn nn n hi (b n c, i mng).

3.2.2. Ph ng php khai bo lin kt SpringPh ng php gn lin kt Spring:

Chn im cn gn linkt Restraint. Vo menuAssign Joint/Point Point Springs .

Nhp cc bc t do b khng ch vo:

+ Translation X, Y, Z : cng ca lin kt nhi theo ph ng X, Y, Z.

+ Rotation about XX, YY, ZZ : cng ca lin kt n hi xoay quanh trc XX, YY,ZZ.


17/176


Hnh 1. 10 Hp thoi AssignDiaphragm.

3.3. Lin kt Constraints

3.3.1. Khi nim chungCc im c cng chung mtConstraint s c mt s chuyn v nh nhau. S l ngchuyn v cng nhau ph thuc votng loi Constraint.

Khi khai bo Constraint, s l ng ph ng trnh tnh ton s gim. Do vy tc tnh tons tng ln. D i y trnh by mt s dng Contraint th ng dng.

Diaphragm , rng buc chuyn v theo mt mt phng. Tt c cc im c gn cngmt Diaphragm u c hai chuyn v trong mt phng ca Diaphram v mt chuyn vxoay vung gc vi mt phng nh nhau. M hnh ny th ng c s dng mhnh ha sn l tuyt i cng trong mt phng khi tnh ton nh cao tng.

Body constraint , dng m t mt khi hay mt phn ca kt cu c xem nh lmt khi cng (Rigid body). Tt c cc nt trong mt Body u c chuyn v bngnhau.

Plate Constraint , lm cho tt c cc nt b rng buc chuyn v cng vi nhau nh lmt tm phng c cng chng un ngoi mt phng bng v cng (ng c viDiaphram).

Beam Constraint , tt c cc nt gn cng mt Beam Contraint c chuyn v cng nhau

nh l mt dm thng c cng chng un bng v cng (khng nh h ng nbin dng dc trc v bin dng xon ca dm).

Ch : Sap2000 cung cp tt c cc loi Contraint ni trn cn Etabs ch cung cpchc nng Diaphram Constraint.

3.3.2. Cch khai bo Chn im cn gn lin kt Contraint.

Vo menu Assign Joint/Point Rigid Diaphragm .

3.3.3. ng dngGip ng i dng m hnh chnh xc s lm vicca kt cu v gim thi gian phn tch tnh tonkt cu.


18/176


Hnh 1. 11 S dng chc nng Diaphragm Contraint m hnh ha sn cng.

4. Vt liu4.1. Tng quan v vt liuTrong Etabs, ta c th khai bo nhiu loi vt liu, cc phn t trong s kt cu c thnhn cc loi vt liu khc nhau.

Etabs cho php ta khai bo ccloi vt liunh b tng, thp, nhm Vt liu ngh ng, trc h ng v d h ng.


19/176



Hnh 1. 12 nh ngha cc thnh phn ng sut trong h ta a ph ng vt liu.

Mi mt vt liu u c mt h trc ta a ph ng ring, c s dng nh nghatnh n hi v bin dng nhit theo cc ph ng. H thng ta a ph ng vt liu chp dng cho loi vt liu trc h ng (orthotropic ) v d h ng (anisotropic ). Vt liu ngh ng ( Isotropic material ) c tnh cht vt liutheo ba ph ng l nh nhau.

4.3. ng sut v bin dng ca vt liu (stresses and strains)

4.3.1. Stress ng sut c nh ngha l lc trn mt n v din tnh dc theo cc trc vt liu camt phn t n v ca mt phn t bt k.

Khng phi lc no cng tn ti 6 ng sut trn cc phn t. V d, ng sut 22, 33, 23 s bng khng i vi phn t thanh (Frame Element ), ng sut 33

4.3.2. Strain

s bng khng i

vi phn t tm v (Shell Element ).

Da vo quy lut ng x ca tng vt liu m ta c bin dng ca vt liu .

1

2

2

112

dxdu

dxdu

+= 1

111

dx

du=

1

3

3

113

dxdu

dxdu

+= 2

222

dxdu

=


20/176


2

3

3

223

dx

du

dx

du+=

3

333

dx

du=

4.4. Cc thng s khai bo vt liu khai bo vt liu, bn vo menuDefine Material Properties Add New Material .

Hnh 1. 13 Hp thoi khai bo vt liu.

Cc thng s:

Material Name tn loi vt liu. Do ng i dng t, nn t tn theo loi vt liu s dng, v d: b tng mc 200 ta k hiu BT200.

Type of Material loi vt liu, chng ta c cc loi vt liu sau:

+ Isotropic vt liung h ng (mc nh).

+ Ortho vt liutrc h ng.

+ Anisotropic vt liud h ng.

Mass Volume : khi lng ring dng tnh khi l ng ring ca phn t trong biton ng.

Weight Volume : trng l ng ring ca vt liu tnh trng l ng ring ca phn t trong cc tr ng hp ti trng, hay cn gi l ti trng bn thn.

Modulus of Elastic E m un n hi, dng xc nh cng ko nn v un. Ethay i theo mc BT. Tham s E cng vi tit din quyt nh bin dng ca kt cu.

Poisson Ratio factor h s Pot Xng () dng xc nh G = E/2/(1+) quyt nhbin dng tr t v xon.


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+ i vi vt liu b tng =0.18 0.2.

+ i vi vt liu thp spx 0.3.

5. Ti trng v t hp ti trng5.1. Ti trngKhi phn t bin b bin dng d i tc ng ca ngoi lc, cc phn t vt cht trongphn t chuyn ng, pht sinh ra gia tc chuyn ng v k m theo l lc qun tnh.

Nu gia tc l nh, lc qun tnh b th c th b qua lc qun tnh so vi cc ti trngkhc. Khi bi ton c gi l bi ton tnh (Static ).

Ng c li khi gia tc ln, lc qun tnh ln, ta khng th b qua lc qun tnh. Lc , tagi l bi ton ng (Dynamic ).

Ngoi ti trng tnh v ng ta cn c ti trng thay i theo thi gian (Time history ).

i vi ti trngtnh, trong Etabs ta c cc tr ng hp ti trng sau

Dead Load : tnh ti Wind load : titrng gi Snow Load : ti trng tuyt

Live Load : hot ti Quake Load : ti trng ng t

Cu hi Ti sao ti trng ng t v ti trng gi ng li nm trong mc Static Load Case (ti trng tnh)?

V chng ta tnh ton ti trng ng t v gi ng theo ph ng php ta tnh (cngha l quy v cc lc tnh ri t n vo kt cu, sau tnh ton ra m men,chuyn v)

Nu chng ta khngdng ph ng php t a tnh tnh ti trng gi ng v ng t,thchng ta khng c php cho loi ti trng ng ny vo mcStatic Load Case .

H s Self Weight l g, ly bng bao nhiu?

H s Self Weight l h s tnh n ti trng bn thn ca phn kt cu c v trongSap (Etabs). Gi s tr ng hp ti c tn l TT c khai bo l Dead Load , h s Self Weight ly bng 0.5, khi ngoi cc ti trng m ta gn vo cho tr ng hp ti TT n cn bao gm ti trng bn thn ca kt cu, nhn vi h s 0.5 ni trn.

Ti trng bn thn ca mt phn t tnh bng trng l ng trn mt n v th tch cavt liu (khai bo trong phnDefine Materials) nhn vi th t ch ca phn t .


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Ti trng bn thn ca kt cu c khai bo theo cch trn , lun c h ng theo

chiu m ca trc Z (Global Coordinates). Thng th ng, h s Self Weight ny ly bng n = 1.1 (n l h s v t ti i vi phn

kt cu c lm bng b tng ct thp).

5.2. T hp ti trng

5.2.1. Cc cch t hp ti trng T hp ng i dng ng i dng t nh ngha tn t hp, t nh nghacc thnh

phn to nn t hp v h s ca chng. V d, theoTCVN mt trong cc t hp cbn th hai l TT+0.9HT+0.9GX (TT tnh ti, HT hot ti, GX : Gi thi theoph ng X)

T hp t ng (Defaut Combo ). Cc t hp ny s t ng sinh ra khi chng ta tinhnh bi ton thit k thp theo tiu chun c sn m Sap (Etabs) cung cp. S cctr ng hp t hp v h s ca cc tr ng hp ti trng tham gia vo t hp ph thucvo tiu chun thit k m ta chn. Cc t hp ti trng ny th ng c tn l DCom1,DCom2,DSTL

5.2.2. Cc loi t hp ti trng ADD: t hp theo ph ng php cng tng thnh phn ca t hp.

ENVE : t hp bao ni lc.

SRSS : cn bc haica tng bnh ph ng cc tr ng hp ti.

ABS: tngtr tuyt i ca cc tr ng hp ti.

Cu hi

Kiu ti trng Live Load, Wind Load c ngha g khng.

i vi bi ton s dng t hp ng i dng v trong bi ton tnh (Static ), th vic khaibo cc kiu ti trng ny khng c ngha g c.

i vi bi ton s dng t hp ti trng t ng. Cc kiu ti trng ny s gip Sap(Etabs) nhn bit c cc tr ng hp ti (tnh ti, hot ti). Da trn tiu chunthit k m bn c khai bo, ch ng trnh Sap (Etabs) s cung cp cc tr ng hp thp ti trong v cung cp cc h s ca cc tr ng hp ti trng trong tng tr ng hpt hp ti tr ng.

Bn cht ca t hp trong Etabs (Sap) l t hp ti trng hay t hp ni lc?


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Bn cht ca kiu t hpAdd trong Sap (Etabs) l t hp ti trng.

Biu bao (t hp Enve) l biu bao ni lc ca cc tr ng hp ti hay l biu ni lc trong tr ng hp bao ca cc tr ng hp ti trng?

L ph ng n th nht : biu bao ni lc ca cc tr ng hp ti trng khai botrong Enve.

Nu khai bo vt liu lm vic trong giai on n hi tuyn tnh, th ti trng v ni lc t l tuyn tnh vi nhau. Khi t hp ti trng v t hp ni lc c g khc nhau khng?

Khc nhau, v bn cht ca t hp ni lc theo TCVN khng n gin l cng tng ccthnhphn ni lc.

5.2.3. Cch khai bo khai bo t hp ti trng, bn c vo menuDefine Load Combination Add New Combo.Hp thoiLoad Combination Data hin ln.

Load Combination Name : Tn h hp ti trng

Load Combination Type : Kiu t hp ti trng trnh by trn.

Case Name : Cc tr ng hp ti trng, nhnnt Add thm vo,Modify sa i vDelele xa i.

Scale Factor : h s t hp.

6. Bi ton phn tch6.1. Cc dng phn tch kt cuPhn tchLinear : bi ton phn tch tuyn tnh.

Phn tchNonlinear : bi ton phn tch phi tuyn. 6.2. Modal Analysis

6.2.1. Tng quanBi ton phn tch Modal l bi ton gii quyt cc vn lin quan n dao ng ringnh tnh ton chu k, tn s, chuyn v ca cc dng dao ng ring ca cng trnh.

Modal analysis c nhngha trongAnalysis Case , bn c th nh ngha nhiu bi tonModal Analysis trong mt cng trnh.


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C hai dng phn tch Modal Analysis:

Eigenvertor , dng xc nh cc dng dao ng ring v tn s dao ng ring cachng. Chng ta th ng s dng cch ny tnh ton tn s dao ng ring kt cucng trnh.

Ritz vertor , dng tm dng dao ng khi ch r cc lc thnh phn to nn daong. Ritzvertor c th cho ta kt qu tt hn i vi cc bi ton v ti trng phhoc ti trng thay i theo thi gian (response spectrum or time history analyses ).

6.2.2. Eigenvertor Analysis

6.2.2.1. Ph ng trnh Eigenvertor

Trong

K l ma trn cng.

M l ma trn khi l ng.

l ma trn Eigenvalue (gi tr ring).

l ma trn eigenvertors (vector ring) t ng ng gi tr ring, n biu thi cho dng

dao ng.Eigenvalue l bnh ph ng ca tn s gc . Cc gi tr tn s v chu k c tnh nh sau:

6.2.2.2.

Number of modesNumber of modes l s dng dao ng cn tnh ton do ng i dng t khai bo cho phnmm bit.

6.2.2.3. Frequency Range

Frequencey Range ldi tn s. Gii tn s c khai bo vo trong Sap (Etabs) qua ccthng s sau:

Shift : Gi tr trung tm ca gii chu k cn tnh (center of cyclic frequency range ).

Cut : Bn knh ca gii chu k cn tnh (Radius of the cyclic frequency range ).

iu c ngha l |f Shift|


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6.2.2.4. Convergence Tolerance

Convergence Tolerance l dung sai hi t. N ch ctrong tr ng hp c khai bo Shift hocCut .

Gi 0 l gi tr ban u 0 tm c s c dng

= 2 Shift.

.

Khi dung sai hi t s tol s c dng nh sau:

Dung sai hi t trong tr ng hp khng khai bo Shift v Cut, khi Tol c 2 dng sau:

hoc

7. Diaphragm Centers of Rigidity, Centers of MassKhai bo tnh ton tm cng: Analyze menu Calculate Diaphragm Centers of Rigidity .Khi Menu ny c nh du, Etabs s tnh ton tm cng trong qu trnh phn tch ktcu.

Tm cng c xc nh bng cch tnh ton ta t ng i (X, Y) ca tm cng vimt im no , thng th ng ng i ta la chn im bt k ny l tm khi l ng(Center of mass ). Ng i ta tnh ton tm cng ca mtDiaphragm da trn ba tr ng h pti trng sau, ti trng n v tc dng vo tm khi l ng:

Tr ng hp 1 (Case 1 ): Lc n v tc dng vo tm khi l ng theo ph ngGlobal X .Lc ny gy ra m men xon Diaphram l Rzx.

Tr ng hp 2 (Case 2 ): Lc n v tc dng vo tm khi l ng theo ph ngGlobal Y .Lc ny gy ra m men xon Diaphram l Rzy.

Tr ng hp 3 (Case 3 ): Vector m menxon n v tc dng vo tm khi l ng theo ph ng Global Z . Lc ny gy ra m men xon Diaphram l Rzz. Khi ta (X, Y) ca tm Diaphram s c xc nh nh sau: RzzRzyX /= v

RzzRzxY /= . im ny l mt thuc tnh ca kt cu, khng ph thuc vo bt k titrng no. Nh vy, vic xc nh tm cng ca tng tng (i vi kt cu nh cao tng)s c Etabs tnh ton da trn ba tr ng hp ti trng trn.


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Hnh 1. 14 Ba tr ng hp ti trng.

xem kt qu phn tch,bn c voDisplay menu Set Output Table Mode , sao tch voBuilding Output trong hp thoi Display Output Tables . Sau xem bngTheCentroids of Cumulative Mass and Centers of Rigidity (Bng tm khi l ng tch ly vtm cng).

Hnh 1. 15 Bng Center Mass Rigidity.

MassX : Khi l ng Diaphram theo ph ng X. XCM : Ta tm khi l ng.

XRC : Ta tm cng.

Cu hi

Tm cng ca floor c lin quan n vch khng?

Theo ph ng php tnh trnh by nh trn th c.

Tm cng ca tng c b nh h ng bi cng ca tng trn v d i n khng? Theo ph ng php tnh nh trn th c.

Tm cng ca mt floor diaphragm c b nh bi vch cng ca nh kh ng?

Theo ph ng php tnh nh trn th c.

Khi l ng ca mt diaphragm c bao gm ct, dm, sn v vch kh ng?

Ty theo cch khai bo diaphragm:


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+ Diaphragm c khai bo thng qua phn t Area, th khi l ng ca mt

diaphragm s bao gm c ct, dm, sn, vch v khi l ng tp trung ti nt csn i qua. Trong cch khai bo ny, khi l ng tp trung ti nt khng c sn iqua s khng c tnh vo khi l ng ca Diaphragm.

+ Diaphragm c khai bo thng qua phn t Joint, th khi l ng ca mtdiaphragm s ch bao gm ct, dm v khi l ng tp trung ti nt (ni cch khcl bao gm Joint, Frame, Area).

+ Thng th ng, ng i ta s dng c hai cch ny gn Diaphragm cho mt tng.V khi lm nh th, khi l ng ca Diaphragm s l khi l ng ca c tng (ct,dm, sn v nt).

Cn l u thm cch tnh khi l ng ca Etabs l cc Frame, Area (ty theo hai cchkhai bo trn) s c quy i v cc nt. Khi l ng ca mt diaphragm s bngtng khi l ng cc nt ca diaphragm .

Cng t ng t nh khi l ng, cng ca mt diaphragm cng c tnh da trnhai ph ng php khai bo trn.


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Ch ng 2: Kt cu h thanh 28

Ch ng 2: Kt cu h thanh

1. Tng quan v phn t thanh 1.1. Phn t thanh (Frame Element)

1.1.1. Khi nim

Khi nim chung: phn t c kch th c mt chiu ln hn nhiu kch th c hai chiucn li c gi l phn t thanh.

Phn t thanh (Frame ) trong Etabs l mt on thng ni hai im, im u (Start )gi l im I, im cui (End ) gi l im J.

Hnh 2. 2 Minh ha mt phn t Frame.

1.1.2. ng dng

Phn t thanh th ng c s dng m hnh ha dm, ct1.2. H trc ta a ph ng (Local Coordinate System)

1.2.1. Khi nimMi phn t Frame u c mt h trc ta a ph ng xc nh tit din, ti trng vni lc. H trc ta a ph ng gm ba trc ta : trc 1 mu , trc 2 mutrng, trc 3 mu xanh.

1.2.2. Mc nh

Mc nh, trc 1 dc theo on thng v h ngt I sang J. Mc nh trc 2 v trc 3 ph thucvo loi phn t Frame (Column, Beam hay Brace ).

Phn t Frame thng ng (Vertical LineObjects ).

+ Trc 1 dc theo on thng. Chiu d ng ca trc 1 l chiu d ng ca trc Z(h ng ln trn).

Hnh 2. 3 H ta a ph ng 123.


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+ Trc 2 vung gc vi on thng. Chiu d ng ca trc 2 l chiu d ng ca trc

X.+ Trc 3 vung gc vi on thng. Chiu d ng ca trc 3 xc nh theo quy tc

bn tay phi.

Phn t Frame nm ngang (Horizontal Line Objects)

+ Trc 1 dc theo on thng. Hnh chiu chiu d ng ca trc 1 ln trc OX trngvi chiu d ng ca trc X. Nu hnh chiu ca on thng ln trc OX bngkhng, c ngha l on thng song song vi trc OY, khi chiu d ng ca trc1 s trng vi chiu d ng ca trc OY.

+ Trc 2 vung gc vi on thng. Chiu d ng ca trc 2 trng vi chiu d ngca trc Z (h ng ln trn).

+ Trc 3 vung gc vi on thng v nm ngang. Chiu d ng ca trc 3 tun theoquy tc bn tay phi.

Frame khng thng ng v cng khng nm ngang (Other neither vertical nor horizontal )

+ Trc 1 dc theo on thng. Chiu d ng ca trc 1 h ng ln trn. C ngha lhnh chiu ca trc 1 ln trc OZ c chiu d ng trng vi chiu d ng ca trc

OZ. + Trc 2 vung gc vi on thng. Mt phng trc 1-2 thng ng. Chiu d ng

ca trc 2 h ng ln trn. C ngha l hnh chiu ca trc 2 ln trc OZ c chiud ng trng vi chiu d ng ca trc OZ.

+ Trc 3 vung gc vi on thng v nm ngang. Chiu d ng ca trc 3 tun theoquy tc bn tay phi.

1.2.3. Hiu chnhGing nh Sap, Etabs cho php ta nh ngha lih ng trc 2 v trc 3 ca on thng bng cchxoay quanh trc 1 mt gc no . Cch lm nh sau:

Chn i t ng Frame cn hiu chnh.

VoAssign menu Frame/Line

Chn mt trong cc Option sau:

Local Axes Hp thoiAxis Orientation hin ln.

Hnh 2. 4 Hp thoi AxisOrientation.


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2.2. Thanh c tit din thay i (Non-Prismatic Sections)

Cng nh Sap, Etabs cho php ta nh ngha thanh c tit din thay i. Chc nng ny c cung cp trong menu Assign Frame Section Add Nonprimastic . khai bothanh c tit din thay i, u tin bn phi c t nht hai loi tit din khai bo. Titdin thay i c th bin i u hoc git bc

Cc la chn cho cng chng un EI ca thanh:

Linear : gi tr EI thay i tuyn tnh theo chiu di ca on.

Parabolic : gi tr2 EI thay i tuyn tnh theo chiu di ca on.

Cubic : gi tr2 EI thay i tuyntnh theo chiu di ca on.

Cc la chn ca Length Type :

Variable : tnh theo chiu di t ng i. V d nh vo 0,5 th l 0,5 chiu di cathanh.

Absolute: tnh theo chiu di tuyt i. V d nh vo 0,5 th l 0,5m hoc 0,5mm,ph thuc vo n v hin hnh ca Etabs l ang l m hay mm.

V d:

Chn n v l Ton-m.

To h l i bt k.

Vo menuDefine Frame Section chn Add Rectangular trong hp thoi Define Frame Properties nh hnh bn nhngha tit din hnh ch nht.

Chng ta nh ngha hai tit din hnh ch nht c tn lFsec2 v Fsec3 nh hnhd i.


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Sau chng ta kch vo Add Nonprimastic trong hp thoi

Define Frame Properties nh hnh bn nh ngha tit dinthay i.

in vo hp thoiNonprimastic Section Definition nh sau:

KchOK thot khi tt c cc hp thoi.

Bn c vo ca s Etabs, v mt ci ct vi tit din lVAR1.Ta c kt qu nh hnh bn.

2.3. Tit din khng c hnh dng xc nh (General)Khi chng ta gp mt tit din phc tp, khng th v bng Section Builder hoc SectionDesigner. Bn c th khai bo n l tit din General. Tit din General l tit din khngc hnh dng xc nh, bn s phi khai cc c tr ng hnh hc nh m men qun tnh,m men xon cho chng.

Tit din General th ng dng trong bi tp c hc kt cu hoc kt cu m tit din l t

hp ca nhiu tit din c bn. Ph ng php khai bo tit din General nh sau:


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Hnh 2. 5 Hp thoi nh ngha tit din General.

VoMenu Define Frame Section chn Add General . Hp thoi hin ln nh hnh 2.4.Cc thng s nh sau:

Corss Section (Axial) Area: din tch tit din ct ngang ca frame (A).

Tosional Constant: m men qun tnh chng xon (J).

Momen of Inertial About : m men qun tnh quay quanh (3 =trc3) (I33, I22).

Shear Area : din tch chu ct (As).Do s phn b khng u ca ng sut tip nnAs khc vi A .

Section Modulus About 3(2) Axis: m men chng un (W=I/ymax; Ch nht W=bh2/6).

Plastic Modulus About 3(2) Axis: m men do (Wp=W/1.3).

Radius of Gyration About 3(2): bn knh qun tnh (r2=I/A).

(Xem thm phn Sap2000)

2.4. Thay i thng s tit din

2.4.1. Thng s hnh hc v c hc ca tit din Cc thng s v c hc ca tit din ph thuc vo khai bo vt liu nh chng ta nitrong phn tr c:

Modulus of elasticity , e1, module n hi, dng cho cng dc trc v c cngchng un.

Shear modulus , g12, module chng ct, dng cho cng chng xon v cngchng ct ngang. g12 c tnh t h s Poisson u12 v e1.


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Mass density : khi l ng ring (khi l ng trn mt n v th tch), m, dng tnh

khi l ng ca phn t (element mass). Weight density : trng l ng ring (trng l ng trn mt n v th tch), w, dng n

tnh ti trng bn thn (Self Weight Load).

Design type indicator , ides, (ch s kiu thit k), dng quy nh kiu phn t s c thit k l thp (steel ), b tng (concrete ), nhm (aluminum), coldformed steel,hoc khng thit k (no design ).

Khi khai bo tit din, cc thng s v c hc s ph thuc vo hnh dngtit din (nus dng loi tit din c sn) hoc ph thuc vo cc thng s khai bo nu s dng titdin dng general. V c bn chng ta c 6 thnh phn c hc sau:

Cross-sectional area , a, din tch mt ct ngang. Khi cng dc trc ca tit dinc dng (a.e1).

Moment of inertia, i33, m men qun tnh trc 3 dng xc nh kh nng chng unca thanh trong mt phng 1-2. Moment of inertia, i22, m men qun tnh trc 2 dngxc nh kh nng chng un ca thanh trong mt phng 1-3. T ng ng vi n ta c cng chng un c xc nh theo cng thc (i33.e1) v (i22.e1).

Torsional constant , j, m men qun tnh chng xon. cng chng xon c xcnh theo cng thc (j.g12). Ch rng m men qun tnh chng xon ch ging mmen qun tnh cc (polar moment of inertia ) trong tr ng hp tit din trn, tt c ccloi tit din khc hai thng s ny l khc nhau.

Shear areas , as2 v as3, din tch chng ct, dng xc nh cng chng ctngang trong mt phng 1-2 v 1-3. T ng ng vi n ta c cng chng ct ngang(as2.g12) v (as3.g12). V ng sut ct ngang ca tit din c dng parabole v tmax ti ng trung ha ca tit din, do vy khi tnh ton bin dng ct ngang chngta phi nhn vi mt h s iu chnh (theo sc bn vtliu). Trong Sap v Etabsng i ta tch hp vo trong din tch chng ct ngang. Do vy as2 v as3 khc a. Vas2, as3 c xc nh nh sau (trch theo ti liu ca sap):


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ta khai bo tit din ch I, sau iu chnh m men qun tnh theo trc X ln 2 ln, din

tch ct ngang tng 2 ln Sap v Etabs cho php ta hiu chnh cc thng s nh sau: Axial stiffness (a.e1): cng dc trc.

Shear stiffnesses (as2.g12) and (as3.g12): cng chng ct ngang.

Torsional stiffness (j.g12): cng chng xon.

Bending stiffnesses (i33.e1) and (i22.e1): cng chng un.

Section mass a.m + mpl .

Section weight a.w + wpl.

Trong wpl v mpl l phn khi l ng hoc trng l ng s cng thm vo, n v ltrong l ng, khi l ng trn mt n v di, s dng i vi dng thanh c tit din thayi. Mc nh, cc gi tr ny bng khng i vi mi tit din.

Ta c 2 cch gn t s ny:

Gn cho tt c cc thanh c cng tit din.

Gn cho mt s tit din no .

3. Lin kt gia hai phn t

3.1. im chn (Insertion point)

3.1.1. Khi nimMc nh, trc 1 ca phn t chy dc theo trc trung haca tit din (hay trng tm ca tit din i vi tit dindi xng). Do vy, ti giao im ca dm mi v ct, dmmi s b nh ln trn. Etabs cho php ta chnh li giaoim ny bng chc nng Intersection Point. Chc nngny s gip ng i dng thit lp m hnh mt cch chnh

xc.Cardinal Point c nh ngha l mt trong m i mtim c m t trong hnh 2. 5.

Hnh 2. 6 Hp thoi Frameinsertion Point


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3.1.2. Ph ng php khai boPh ng php khai bo nh sau:

Chn Frame cn thay i Intersection Point.

Chn Assign menu Frame/Line

Khi bn ch nh im chn, Etabs s tnh ton li h ta a ph ng ca phn t.Mt cch t ng t, ti trng gn vo phn t cng s da trn chiu di sau khi tnhli h ta a ph ng. Hnh v 2.8 th hin s tnh ton li h ta a ph ngcng nh chiu di thc ca cu kin.

Insertion Point ,hp thoi Frame Insertion Point hin ln (hnh 2.6).

Hnh 2. 8 V tr cc im chn.

Hnh 2. 7 S dch chuynca dm.


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Hnh 2. 9 M t cch chnh Cardinal Point ca dmv ct sao cho tm ca dm v ct khng trng khp vi nhau.

Nu bn khng tch vo nt Do not transform frame stiffness for offsets from centriod ths dch chuyn s khng nh h ng g n kt qu ni lc. Nu tch vo th:

cng ca thanh s thay i.

Tng ti trng tc ng vung gc vi thanh thay i (do chiu di ca thanh thayi).


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Chi tit xem thm trong phn bi tp 4, bi tp m hnh nh cng nghip.

3.2. im giao (End offsets)

3.2.1. Khi nimPhn t thanh trong kt cu c m t bi ng trc ni hai nt ca thanh. Mt iu tra l ti im giao gia cc phn t Frame (v d nh dm v ct), phn tit din ca haiFrame ti im giao (cross-sections ) s b chng ln nhau (overlap). Etabs cung cp chcnng End Offsets cho php ta nh ngha li on tit din b chng nn nhau ny.

Mc nh chiu di ca thanh tnh c phn thanh b giao vi ct (hnh v 2.9). Vic tr phn giao nhau ca gim vi ct c kch th c ln s lm gim chiu di tnh ton cathanh dm mt cch ng k. Do vy Etabs cho php ta k n chiu di vng cng cadm giao vi ct thng qua 2 tham s (End-I) v (End-J). Khi chiu di tnh ton cadm s c tnh theo cng thc sau.

Lc= L Rigid * (EndI + EndJ)

Trong :

Lc l chiu di tnh ton ca thanh

L l chiu di thc ca thanh

Rigid l h s cng (ly gi tr t 01). H s ny dng thay i kch th c Ioff,Joff (cng thc tnh: Joff=EndI*Rigid. Joff=EndJ*Rigid).

Hnh 2. 10 End offsets gia dm v ct.

3.2.2. Ph ng php khai b oVomenu Assign Frame/Line End (Length) Offsets .


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Automatic from Connectivity : Etabs s t ng tnh li

chiu di tnh ton ca Frame. + i vi ct (Columns), End offset s tnh da trn

kch th c ln nht ca cc dm ni vi ct.

+ i vi dm (Beams ), End offset s tnh da trnkch th c ln nht ca cc ct ni vi dm.

Define Lengths: Bn c th nhp trc tip End-I vEndJ thng qua la chn ny.

Rigid-zone factor : L h s cng, h s ny cho

php ng i dng c th iu chnh li EndI v EndJ(xem cng thc tnh trong mc trn).

3.3. Lin kt Release (Frame Releases and Partial Fixity)

3.3.1. Khi nimNh ta bit, mi u ca Frame u c su bc t do. Ti nhng v tr ny, Etabs chophp ta gii phng bt bc t bin n thnh cc loi lin kt khc (khp, ngm xoay)nh hnh v d i y.

Hnh 2. 12 Frame Element End Releases.

Nhn trn hnh v 2.11, thanh xin (diagonal element ) lin cng ti im I v lin kt khpti im J. Hay ni cch khc ta gii phng lin kt xoay (R2, R3) ti im J. Khi mmen ti im J s bng khng.

Etabs chia vic gii phng lin kt lm 2 loi:

Hnh 2. 11 Hp thoiFrame End Len th Offsets.


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Unstable End Releases : Gii phng lin kt khngn nhgy ra h bin hnh (thanh

c tch ra khi h hoc mt s chuyn v no ). Stable End Releases : Gii phng

lin kt vn m bo h bt binhnh.

3.3.2. Ph ng php khai bo Chn phn t Assign menu Frame/Line Frame Releases/Partial Fixity . Hp thoi Assign Frame

Release hin ln nh hnh 2.12: Start, end : lin kt ti im u (I),

cui (J) ca thanh.

Vi chc nng Frame Partial Fixity Springs , bn c th thay lin ktcng bng lin kt n hi ti u I v J ca thanh. n v in vo l force/lengthhoc moment/radian. Mun gn lin kt n hi vo u thanh, tr c tin phi giiphng lin kt ti u thanh .

4. T ng chia nh phn t (Automatic Frame Subdivide)4.1. Khi nimTrong qu trnh phn tch, Etabs t ng chia nh phn t Frame nucn thit. Trong mts tr ng hp, bn c th khng mun t Etabs t ng chia nh phn t. Chc nngLine Object Auto Mesh Options cho php bn kim sot ch t ng chia nh ny. L u rng, chc nng ny hon ton khc vi chc nngEdit menu Divide Line.

4.2. Ph ng php khai bo

Chn phn t Line cn kim sot chn Assign menu Frame/Line Automatic Frame Subdivide , hp thoi Line Object Auto Mesh Options hin ln.

Thng s chi tit trong hp thoiLineObject Auto Mesh Options c in giinh sau:

Auto Mesh at Intermediate Points :chia nh phn t c chn ti nhng

Hnh 2. 13 Hp thoi Assign Frame Releases

Hnh 2. 14 Hp thoi Line Object AutoMesh Option.


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im nm dc trn phn t, cc im ny l cc im ca cc phn t khc hoc l

cc im mesh ca phn t Area (xem thmArea Mess Options trong ch ng 3). Auto Mesh at Intermediate Points and Intersecting Lines/Edges : chia nh phn t

c chn ti nhng im nm trn phn t v ti giao im ca cc phn t.Mcnh, Etabs p dng ch chia nh ny trong qu trnh phn tch tnh ton ni lc.

No Auto Meshing : Etabs khng chia nh phn t c chn trong qu trnh thchin bi ton phn tch.


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Ch ng 3: Kt cu tm v 44

Ch ng 3: Kt cu tm v

1. Phn t Tm bn1.1. Phn t Area (Area Element)

1.1.1. Khi nim chungPhn loi kt cu tm v trong Etabs:

Slab : kt cu bn sn. Wall : kt cu t ng b tng,vch.

Phn loi theo tnh cht chu lc:

Membrane phn t mng, ch chu ko hoc nn trong mt phng, m men theoph ng php tuyn c th c b qua.

Plate phn t tm, ch chu un v chu ct.

Shell phn t tm v, chu un ngoi mt phng, ko hoc nn trong mt phng. L

tng hp ca hai phn t Membrane v Plate. 1.1.2. Thickness Formulation (Thick Thin)Sap2000 v Etabs cung cp hai dngThickness Formulations cho php ta k n hockhng k n hiu ng bin dng ct trong phn t Plate hoc Shell element:

Dng Thickplate (Mindlin/Reissner), bao gm hiu ng bin dng ct ngang.

Dng Thinplate (Kirch hoff), b qua hiu ng bin dng ct ngang.

Bin dng ct s tr ln quan trng khi b dy ca shell ln hn 1/10 1/5 nhp. Chngcn c th c k n ti nhng v tr c m men un tp trung nh gn nhng v tr cs thay i t ngt v b dy, hoc ti v tr gn gi , hoc nhng v tr gn l thng

Vic phn bit r rng hai tr ng hp tm dy v mng rt nhy cm. v n cn ph thucvo hnh dng tm, t s b dy trn chiu di cnh v ph thuc vo vic chia l i (meshshell ). Do vy, ng i ta khuyn co rng bn nn s dng Thickplate Formulation tr phibn khng nh rng bin dng ct l nh (shearing de formations will be small ), hoc bnmun th nghim l thuyt tnh ton tm mng, hoc bn ang s dng l i chia mo m(v s chnh xc ca l thuyt tnh ton ThickPlate b nh h ng bi s chia l i mo m(mesh distortion ) hn l ThinPlate).


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Ch : Thickness formulation khng c tc dng i vi phn t mng (membrane ),

ch xy ra i vi tm chu un (plate or shell ).

Hnh 3. 1 Mt ct ngang ca tm c lc ct ln ti ni thay i cng tit din.

Hnh v 3.1 th hin ni c tit din thay i, ti ni c tit din thay i s sinh ra lc ctv ng sut ct. T s sinh ra bin dng ct. Vy trong tr ng hp ny, vic khai bohiu ng bin dng ct l cn thit, tc l m hnhThickplate (Mindlin/Reissner) l hpl.

1.1.3. ThicknessMi mt ct shell u c hng s b dy mng (constant membrane thickness ) v hngs b dy un (constant bending thickness ).

Hng s b dy mngth c s dng tnh ton:

cng mng (ko nn trong mt phng v xon ngoi mt phng) cho phn t shell(full-shell ) v phn t mng thun ty (pure membrane ).

Th tch phn t. Vic tnh ton th tch phn t s lin quan n trng l ng bn thnca phn t v khi l ng bn thn ca phn t. Tc l lin quan n bi ton tnhton dao ng (Dynamic analyse ) v ti trng bn thn ca cng trnh.

Hng s b dy unthb dng tnh ton:

cng chng un ca tm chu un (plate bending stiffness ) cho phn t shell (full-shell ) v phn t tm (pure plate ).

Thng th ng th hai b dy trn l bng nhau. Tuy nhin, hai b dy ny s khc nhaui vi mt s ng dng nh m hnh ha b mt nhn, hoc n c nh vic thin v anton, ta ly thb = h0 = h a (h l b dy sn, a l lp bo v) trong bi ton tnh ton btng ct thp.

Ch : chiu dy Membrane (mng) v Bending (un) ni chung l ging nhau. Tuynhin trong mt s tr ng hp, hai thng s ny li khc nhau.

1.1.4. Material AngleH ta vt liu v h ta phn t shell c th khc nhau. Trc 3 ca hai h ta ny lun lun trng nhau tuy nhin trc 1 v trc 2 c th khc. Ty theo yu cu ca biton m ta c gc a nh hnh v:


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Hnh 3. 2 Gc vt liu ca phn t tm v.

Ch : Gc vt liu khng c ngha trong bi ton vt liu ng h ng (isotropicmaterial properties).


1.2.1. Trng thi mc nh

Mi mt phn t shell u c mt h trc ta a ph ng (element local coordinatesystem ), c dng nh ngha vt liu, ti trng v xut kt qu.

Ph ng php xc nh h trc ta a ph ng cho phn t tm v phng (ph ng phpxc nh h trc ta a ph ng cho tm v cong xin c trong schSap Reference trang 137 mcAdvanced Local Coordinate System ).

Trc 3 lun vung gc vi mt phng ca phn t. Chiu d ng ca trc 3 h ng theoquy tc vn inh vt, chiu vn inh l chiu v phn t. V d v theo J1J2 J3 thchiu d ng trc 3 nh trn hnh v 3.3.

Trc ta 1, 2 lun nm trong mt phng ca phn t v c xc nh da trn s t ng quan ca trc 3 so vi trc Z.

+ Mt phng 32 lun lun thng ng, c ngha l song song vi trc Z.

+ Trc 2 theo chiu d ng ca trc Z tr tr ng hp phn t nm ngang, trongtr ng hp ny trc 2 h ng theo chiu d ng ca trc Y.

+ Trc 1 hp vi trc 2, 3 theo quy tc bntay phi.


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Hnh 3. 3 nh ngha cc mt ca phn t tm v.

1.2.2. Bin iTa c th xoay h trc ta a ph ng ca phn t Area. Ph ng php xoay nh sau:

Chn i t ng Area cn thay i h ta aph ng.

Chn Assign menu Area Local Axes bt hpthoi Area Local Axis (hnh 3.4).

+ Angle in Degrees : Gc quay ca trc ta th 2quanh trc 3 ca phn t. Gc d ng c ngha ltrc 2 quay theo chiu kim ng h nu nh trc3 h ng v pha ng i dng. Gc xoay l gc hpbi trc 2 mc nh (default ) vi trc 2 mi.

+ Rotate by Angle : Gc quay ca trc ta th 2quanh trc 3 ca phn t. Gc d ng c ngha ltrc 2 quay theo chiu kim ng h nu nh trc 3h ng v pha ng i dng. Gc xoay l gc hp bitrc 2 hin ti (current ) vi trc 2 mi.

+ Normal to Selected Beam : vo hp thoi ny,bn phi chn mt dm v mt Area tr c khi quay h ta a ph ng. Khi chc

Hnh 3. 4 Hp thoi AssignLocal Axise.

Hnh 3. 5 nh ngha duca gc quay.


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nng ny c chn, Etabs s quay trc 2 ca phn t Area vung gc vi phn t

dm c chn.+ Reverse Normal of Vertical Areas : lt ng c h trc ta 3.

Ch : H trc ta a ph ng ca Pier v Spandrel khng trng vi h trc ta a ph ng ca Area v Frame to ln chng. Do vy ta khng th s dng ph ng phpny xoay h trc ta a ph ng ca Pier v Spandrel.

1.3. Tit din khai bo tit din, ta vomenu Define Wall/Slab/Deck Sections . Nhn chn Combo box Add New nh ngha mi tit din. Cc thng s c cp n trong mc 1.1.

Khi khai bo xong tit din, ta c th chn chc nngModify/Show Section chnhsa cc thng s tit din. c bit bn c c th s dng chc nngSet Modifiers tronghp thoi Wall/Slab Section (hnh 3.6) thay i c tr ng tit din. c tr ng titdinmi s bng cc thng s trong hp thoi Analysis Stiffness Modification Factors (hnh3.7) s c nhn vi c tr ng tit din c.

1.4. Bc t do (Degree of Freedom)Mt phn t Area lun lun c su bc t do ti cc nt ca n. Bc t do ca phn t Plate, Membrane, Shell c m t nh hnh v 3.8.

Hnh 3. 7Analysis Stiffness Modification Factors.

Hnh 3. 6 Hp thoiWall/Slab Section.


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Hnh 3. 8 Bc t do ca cc loi tm.

1.5. Mass Trong tnh ton bi ton ng, khi l ng ca kt cu c s dng tnh ton lc quntnh. Khi l ng phn b ca phn t Area c quy cc nt ca n. Khi l ng ca phnt Area c tnh da trn din tch b mt, b dy th v khi l ng ring m ca vt liu.

Etabs ch quy i khi l ng cho ba bc t do UX, UY v UZ. Khng tnh ton khi l ngm men qun tnh cho ba bc t do xoay.

1.6. Ni lc v ng sut

1.6.1. Ni lc Ni lc c tnh bng cch tch phn ng sut theo chiu dy ca phn t. Phn t Shellc nhng thnh phn ni lc nh sau:

Lc ko nn theo ph ng 1 v 2 (Membrane direct forces ):

+ +

=

2/

2/31111

th

thdxF

+ +

=2/

2/

32222

th

th

dxF

Lc ct(Membrane shear force) :

+ +

=2/

2/

31211

th

th

d F


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M men un (Plate bending moments ):

+ +

=2/

2/

31111

thb

thb

dxt M

+ +

=2/

2/

32222

thb

thb

dxt M

+ +

=2/

2/

31212

thb

thb

dxt M

M men :

+ Membrane direct forces

+

=2/

2/

31111

th

th

dxF

+

=2/

2/

32222

th

th

dxF

+ Membrane shear force

+

=

2/

2/

31212

th

thdxF

+ Plate bending moments

+

=2/

2/

31111

thb

thb

dxt M

+

=2/

2/

32222

thb

thb

dxt M

+ Plate twisting moment

+

=2/

2/

31212

thb

thb

dxt M

+ Plate transverse shear forces

+

=2/

2/

31313

thb

thb

dxV


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+

=2/

2/

32323

thb

thb

dxV

2

12

1

1113

dxdM

dxdM

V =

2

22

1

1223

dxdM

dxdM

V =

1.6.2. ng sut

33

111111

12x

thb

M

th

F = thb

V 1313 =

33

221122

12x

thb

M

th

F = thb

V 2323 =

33

121212

12x

thb

M

th

F = 033 =

Hnh 3. 9 ng sut v ni lc ca phn t tm v.


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Hnh 3. 10 ng sut v ni lc ca phn t tm v.

2. Vch cng2.1. Tng quan v Pier v Spendrel

2.1.1. Khi nimHnh v d i y l mt ct qua cu thangmy, vch c l ca.

+ Pier l vch chu lc chnh.

+ Spandrel l vch ging ngang.

Mt phn t Pier hoc Spandrel c th baogm nhiu phn t Wall v nhiu phn t Frame.

2.1.2. t tn phn t Vic t tn phn t vch s gip ta nh ngha titdin vch trong bi ton thit k mt cch nhanhchng hn v xem kt qu ni lc ca vch mtcch d dng.

Cc t tn vch nh sau:

i vi Pier,

Hnh 3. 11 nh ngha Spandrel v Pier.

Hnh 3. 12 Hp thoi Pier Names.


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+ Chn Area v Frame cn gn tn.

+ gn tn Pier cho phn t Frame, chnAssign Frame/Line Pier Labels .+ gn tn Pier cho phn t Area, chnAssign Shell/Area Pier Labels .

i vi Spandrel,

+ Chn Area v Frame cn gn tn.

+ gn tn Spandrel cho phn t frame, chnAssign Frame/Line Spandrel Labels .

+ gn tn Spandrel cho phn t area, chn

Assign

Shell/Area

Spandrel Labels . gn tn cho Spandrel v Pier c cha c

Frame v Wall, chng ta nht thit phi gn hailn theo hai ph ng php trn. Tuy nhin, thayi hoc xa tn, chng ta khng nht thit philm c hai ng tc trn.


2.2.1. Phn t Pier Trong khng gian ba chiu, h ta a ph ng ca phn t Wall Pier c nh nghanh sau:

Trc 1 ko di t pha d i ln pha trn Pier. Chiu d ng ca trc 1 cng chiu vichiu d ng ca trc Z.

Trc 2 song song vi cnh di ca phn t Pier. Hnh chiu chiu d ng ca trc lntrc OX trng vi chiu d ng ca trc OX. Nu trc 2 song song vi trc OY th chiud ng ca trc 2 s cng chiu vi chiu d ng ca trc OY.

Ph ng v chiu ca trc 3 c xc nh theo quy tc bn tay phi.

2.2.2. Phn t SpandrelQuy tc xc nh h ta a ph ng ca phn t Spandrel nh sau:

Mt phng 1-2 nm trn mt phng ca Wall Spandrel. Trc 1 nm ngang v hnhchiu chiu d ng ca n ln trc OX trng vi chiu ca trc OX. Nu mt phngSpandrel song song vi mt phng Y-Z, th trc 1 s song song v cng chiu vi trcOY.

Trc 2 s h ng ln trn v cng chiu vi trc OZ.

Hnh 3. 13 Hp thoi SpandrelNames.


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Trc 3 lun nm ngang v vung gc vi mt phng spandrel. Chiu d ng ca trc 3

c xc nh theo quy tc bn tay phi. Trong tr ng hp Wall Spandrel c to t nhiu phn t (c Wall v Frame), khi htrc ta a ph ng ca Spandrel vn c xc nh theo quy tc trn. V l u rng,h trc ta a ph ng ca phn t Spandrel lun lun c lp vi h ta aph ng ca cc Wall v Frame to nn n.

2.2.3. Hin th h ta a ph ng Vo menuView Set Building View Options Vo mcPier and Spandrel v chnPier Axes v Spandrel Axes .

Hnh 3. 14 Hp thoi Set Building View Options.

2.3. Tit dinCc b c gn tit din cho Pier v Spandrel:

t tn phn t Pier v Spandrel.

Khai bo tit din cho phn t Pier.

Gn tit din cho phn t Pier.

i vi Spandrel, chng ta ch c mt bi ton thit k. Do vy ta ch cn khai boSpandrel Name m khng cn khai bo tit din.


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2.3.1. t tn phn t Pier v Spandrel

2.3.1.1. Pier Labeling

Bn c c th t tn, xa tn, hoc thay i tn ca Pier thng qua hp thoiPier Names . Ph ng php nh sau:

Chn phn t cn gn tn.

gn phn t Line thnh phn t Pier, chnmenu Assign Frame/Line

gn phn t Area thnh phn t Pier, chnmenu Assign

Pier Labels .

Shell/Area

Trong hp Pier Name : Chn tn Pier cn gncho phn t Line, Area.

Pier Labels .

Chi tit hp thoi:

Add New Name: thm mt tn phn t Pier mi.

Change Name : thay i tn phn t Pier.

Delete Name : xa tn phn t Pier.

2.3.1.2. Spandrel Labeling

Bn c th t tn, xa tn, hoc thay i tn caphn t Spandrel thng qua hp thoiSpandrel Names . Ph ng php nh sau:

Chn phn t cn gn tn.

gn phn t Line thnh phn t Spandrel,chn menu Assign Frame/Line

gn phn t Area thnh phn t Spandrel, chn menu Assign

Spandrel Labels .

Shell/Area

Trong hp Spandrel Name : chn tnSpandrel cn gn cho phn t Line,Area.

Spandrel Labels.

Chi tit hp thoi:

Hnh 3. 15 Hp thoi Pier Names.

Hnh 3. 16 Hp thoi SpandrelNames.

Hnh 3. 17 Hp thoi Pier Section.


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Add New Name: thm mt tn phn t Spandrel mi.

Change Name : thay i tn phn t Spandrel. Delete Name : xa tn phn t Spandrel.

2.3.2. nh ngha tit din Pier Chn menu Design Shear Wall Design

Define General Pier Sections For Cheking ,hp thoi Pier Sections hin ln. to mi mt tit din, nhnAdd Pier Section .

Hnh 3. 18 Hp thoi Pier Section Data.

Section Name : tn ca tit din Pier.

Base Material : vt liu c s ca Pier (ging nh Base Material ca Frame Section ).

Add Pier : thm mt Pier mi (xem phn bi tp hiu hn v hai la chn ny).

+ Add New Pier Section : to mi mt Pier.

+ Start from Existing Wall Pier : nh ngha mi mt Pier t mt hnh dng Pier csn.

+ Hp thoi Combo box th xung nh hnh bn tri xc nh tng cha Pier c sn.

+ Hp thoi Combo box th xung nh hnh bn phi xc nh tn Pier c sn( khai bo phn 2.3.1.1).

Vo menu Define/Edit/Show Section bm vo ntSection Designer bt uchnh sa, hoc nh ngha mi tit din.

(Chi tit tham kho thm phnSection Designer trong ch ng 4 Ph lc)


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Ch : cng nh cc bi ton thit k khc, chng ta c hai bi ton i vi vch

+ Bi ton thit k thp cho vch (Reinforcement to be Designed ).+ Bi ton kim tra thp cho vch (Reinforcement to be Checked ).

2.3.3. Gn tit din Pier Sau khi nh ngha xong tit din vch, ta gn tit din cho vch. Ph ng php thc hinnh sau:

Chn Pier cn gn tit din.

Chn Design menu Shear Wall Design Assign Sections for Checking chn

tip cc chc nng sau: General Reinforcing Pier Section . Hp thoi

Assign General Reinforcing Pier Section hinln.

+ Section at Top : tit din vch pha trn camt tng.

+ Section at Bottom : tit din vch pha d ica mt tng.

Uniform Reinforcing Pier Sections , hp thoiUniform Reinforcement Assignment to Pier hinln.

+ Pier Material : vt liu lm ln tit din.

+ Distributed Bars: distributed bar size (ctthp dc theo cnh ca Pier),spacing and clear cover of the bar (khong cch ct thp v lp bo v).

+ End/Corner Bar Size : thp gc ca Pier.

+ Check/Design : chn hai dng bi ton thit k.

2.4. Ni lc phn t Pier v Spandrel Ni lc ca phn t Wall pier v Wall spandrel t ng t nh ni lc ca phn t Frame.Chng bao gm:

P: lc dc.

V2: lc ct trong mt phng 12.

Hnh 3. 19 Hp thoi AssignGeneral Reinforcing Pier Sections


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V3: lc ct trong mt phng 13.

T: lc xon dc trc. M2: moment xon trong mt phng 13 (quanh trc 2).

M3: moment xon trong mt phng 12 (quanh trc 3).

2.5. Kt qu thit k vch

2.5.1. Pier result DesignChi tit xem phn bi tp vch.

2.5.2. Spandrel Result Design FlexuralDesign.

Shear Design.

Chi tit xem phn bi tp vch.

Bn c th OverWrites, ti hp thoi ny, ta c th khai bo li tt c cc thng s tnhton (chiu dy, chiu su, tiu chun, lp bo v)

3. Chia nh phn t (Area Mesh Options)

3.1. Khi nimTrong qu tr nh phn tch, Etabs t ng chia nh i t ng Area (Deck v Slab). Vicchia nh phn t Area gip phn b ti trng ln cc kt cu mt cch chnh xc hn.V d :

Hnh v 3.20.a, Hnh v 3.20.c,


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Hnh 3. 20 Chc nngArea Object Auto Mesh Options.

Ging nh Subdivide Frame . Area Subdivide cho php chia nh sn mt cch t ngtrong qu trnh tnh ton. Ti mi im chia nh, sn v dm s c chuyn v cng nhau.Vic chia nh sn s lm cho kt qu tnh ton ni lc dm m sn truyn ti ln mtcch chnh xc hn.

Hnh 3. 21 S truyn ti trng t sn vo dm bin.

Hnh v 3.20.b: Chnshell Assign Area Automatic Area Mesh.

Hnh v 3.20.a: S dng No Auto meshing (mc nh khi v area).

Hnh v 3.20.c: L kt qu khi s dng hnh 3.20.a.

Hnh v 3.20.d: L kt qu khi s dng hnh 3.20.b. 3.2. Ph ng php chia nh Chn i t ng Area cn tc ng, chnAssign menu Shell/Area Area Object MeshOptions, hp thoi Area Object Auto Mesh Options hin ln nhsau:

Hnh v 3.20.b, Hnh v 3.20.d,


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Ch ng 4: Ph lc 62

Ch ng 4: Ph lc

1. Section Designer1.1. Tng quanSection Designer l ch ng trnh chy tch hp vo trong Etabs. Cc chc nng c bnca Section Designer:

nh ngha cc tit din Frame (b tng ct thp hoc thp) phc tp khng c sntrong Etabs.

nh ngha cc tit din vch chu lc (Pier Wall ) b tng ct thp hoc thp.

1.2. Cn bn v Section Designer

1.2.1. Khi ng Section Designer T ng ng vi hai chc nng c bn ni trn, ta c haicch khi ng Section Designer trong Etabs.

1.2.1.1. Section Designer For Frame SectionsKhi ng Section Designer cho Frame Sections, ta lmtheo cc b c sau:

Chn Define menu Frame Sections trong Etabs, hp thoiDefine Frame Properties hin ln.

Hnh 4. 2 Hp thoi Define FrameProperties.

Hnh 4. 1 Hp thoi DefineFrame Properties.


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nh ngha thm mt tit din mi, nhn voCombo box v chnAdd SD Section .

Hp thoi SD Section Data xut hin. Cc thng s trong hp thoi ny s c cp c th trong phn 2.1.

Nhn vo ntSection Designer trong hp thoiSD Section Data khi ng ch ngtrnhSection Designer (hnh 4.2).

1.2.1.2. Section Designer For Wall Piers

khi ngSection Designer cho Wall Piers ta lmtheo cc b c sau:

VoDesign menu Shear Wall Design DefinePier Sections for Checking trong Etabs, khi hpthoi Pier Sections s hin ln.

nh ngha mi mt tit din ta bm vo ntAdd Pier Section . thay i tit din c sn bm vont Modify/Show Pier Section.

Hp thoi Pier Section Data hin ln. Cc thng s ca hp thoi ny s c cp n trong mc1.2.2.

Bm vo ntSection Designer trn hp thoi Pier Section Data khi ng ch ng trnhSectionDesigner .

1.2.2. Hp thoi Pier Section DataMc ny trnh by chi tit cc thng tintrong hp thoiPier Section Data .

Section Name : Tn ca tit din Pier.

Base Material : vt liu c s ca Pier (ging nh Base Material ca Frame Section).

Add Pier : thm mt Pier mi (xem phn bi tp hiu hn v hai la chn ny). + Add New Pier Section : to mi mt Pier.

+ Start from Existing Wall Pier : nh ngha mi mt Pier t mt hnh dng Pier csn.

Define/Edit/Show Section bm vo ntSection Designer bt u chnh sa,hoc nh ngha mi tit din.

Hnh 4. 3 Hp thoi Pier Section Data.


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Ch ng 4: Ph lc64

1.2.3. Hp thoi SD Section Data

Mc ny trnh by chi tit cc thng tin trong hp thoi SD Section Data. Section Name : Tn tit din.

Base Material : vt liu c s. S l ng loi vt liu trong Combo Box ph thuc vo s l ng loi vt liu ta khai bo trong Etabs. Vic khai bo vt liu c sphc v chohai mc ch:

+ Xc nh loi bi ton thit k (Thit k b tng ct thp, hay thit k thp).

+ Nu tit din c lm t nhiu loi vt liu, khitnh ton cc c tr ng hnh hc v c tr ng chc ca tit din, Etabs s quy i tt c cc loivt liu v vt liu c s v a ra bo co(report ) v cc c tr ng c hc ca tit din (Section Properties ).

Design Type : Mc ny ch nh r kiu thit k.

Concrete Column Check/Desgin : Ch nh loi biton thit k:

+ Reinforcement to be Checked: Bi ton kim tra

+ Reinforcement to be Designed : Bi ton thit k.

Define/Edit/Show Section bm vo ntSectionDesigner bt u chnh sa, hoc nh nghami tit din.

Hnh 4. 4 Hp thoi SDSection Data.


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1.3. Ch ng trnh Section Designer

1.3.1. Giao din ch ng trnh Section Designer

Hnh 4. 5 Giao din ch ng trnh Section Designer.

1.3.2. H trc ta H trc ta trongCSISD (CSI Section Designer) bao gm haitrc ta X v Y. Trc X lun nm ngang v Y lun thng ng,chiu d ng ca chng c th hin nh hnh v.

1.3.2.1. H trc ta a ph ng ca Frame

Mc nh trc 2 v 3 nh hnh v, trc 1 tun theo quy tc bn tayphi (h ng t gc ta ra pha ng i dng, vung gc vi mtphng mn hnh).

i vi h trc ta a ph ng ca Frame, ta c th xoaychng quanh trc 1.

1.3.2.2. H trc ta a ph ng ca Pier

H trc ta a ph ng ca Pier nh hnh v.

Khng ging nh h trc ta a ph ng ca Frame, h trc ta a ph ng caPier khng th xoay c.


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H trc ta a ph ng ca Pier trong Etabs c cp n trong ch ng 3.

1.3.3. Tit din v hnh dng (Sections and Shapes)Chng ta cn phn bit hai khi nim Section (tit din) v Shape (hnh dng) trongSection Designer. Mt Section khng ch c th cha mt shape m n cn c th chanhiu Shape.

1.3.3.1. Tit din (Section)

Section l mt tit din trn vn c nh ngha trong Section Designer.

H trc ta a ph ng ca section c k hin l trc 2 v 3. Gc ca ta a

ph ng l trng tm ca tit din. 1.3.3.2.

H nh dng (Shape)

Hnh dng hnh hc (geometric shapes ) gip ta thit k tit din mt cch nhanh chng.Section Designer cung cp rt nhiu Shape c sn

Draw menu Draw Structural Shape : Dng v cc hnh dng kt cu nh hnhdng ch I/Wide flange (ch I), Channel (ch C), Tee (ch T), Angle (thp gc),Double Angle (2 thanh thp gc), box/tube (hnh ng), pipe (vnh khuyn) v plate(tm).

Draw menu Draw Solid Shape : Dng v bn hnh dng c l Rectangle (hnhch nht), circle (hnh trn), circular segment (vng trng khuyt) v circular sector (cung trn).

Draw menu Draw Poly Shape : Cho php ng i dng v mt hnh a gic mt cchty .

Vi mi Shape ta c th hiu chnh thuc tnh ca chng bng cch nhn phi chut.

Material : hiu chnh vt liu. Mi mt Shape ch c lm t mt loi vt liu. S l ngloi vt liu c th gn cho Shape ty thuc vo s l ng loi vt liu m ta khai bo

trong Etabs. Dimensions and Location : Kch th c v v tr.

+ V tr ta tm (X, Y Center ).

+ Kch th c chiu rng v chiu cao (Height, Width).

+ Mt s thuc tnh khc ty thuc vo hnh dng Shape.

+ Gc quay (Rotation).

Mu ca shape (Color ).


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1.3.4.2. Phn loi ct thp gia c ng

Hnh 4. 7 Cc loi ct thp gia c ng.

Phn loi ct thp gia c ng:

Loi bm dnh cng vi Shape (hnh 4.7.a). Loi ny c t ng to ra khi tai khai boReinforcement trongthuc tnh ca Shape.

Thp gia c ng thm ti mt v tr bt k.

Thp di u trn mt ng thng (Line Pattern ) dctheo cc ng bin ca shape ( Edges ) (hnh 4.7.b).

Thp ti cc gc (Coner bar ) (hnh 4.7.c)

Thp gia c ng trn Line Pattern dc theo cc ngbin ca Shape (hnh 4.7.d). Chng ta c hai loiLine Pattern nh hnh 4.8.

Thp gia c ng ti gc v thp gia dc theo ng bin ca Shape. Clear Cover l lpbo v thc ca thp (Hnh 4.9).

Hnh 4. 8 Hai loi LinePattern.


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1.3.5. Ph ng php v

Chng ta c th v ring tng Shape, sau v cc ng Line Pattern, hoc ta c th vShape sau chn Reinforcement cho chng.

Mun hin chnh hnh dng hoc v tr ca cc i t ng,chng ta phi nhn vo biu t ngReShaper trn Toolbarshoc voDraw menu ReShape Mode .

kt thc victhit k tit din, cc bn nhn vo ntDone pha bn d i phi ca ca s ch ng trnh.

Ch : Nu cc mt tit din bao gm nhiu Shape ri

rc khng lin kt vi nhau. Trong khi tnh ton, cc Shapeny s lm vic cng nhau.

1.4. Section Properties

1.4.1. Mc ch ca Section PropertiesCc thng s tit din chng ta c th tm thy trongDisplay menu Show SectionProperties . Chc nng ca lnh ny l:

Hin th cc c tr ng tit din (Section Properties ).

Cho php ta xem (khng sa c) vt liu c s catit din (Base Material ). i vi Frame, n cho php ta thay i c h trc ta

a ph ng ca tit din.

1.4.2. Thng s thit dinCng thc tnh s quy i tit din :

Trong : ASection A

din tch quy i (n v di bnh ph ng).

Shape

E

din tch thc ca cc Shape trong Section (khngbao gm ct thp gia c ng), n v chiu di bnh ph ng.

Base modul n hi ca vt liu c s (lc/chiu di bnhph ng).

Hnh 4. 9 Lp bo vct thp.

Hnh 4. 10 Hpthoi Properties.


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EShape

n s l ng Shape trong mt Section.

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