Upload
angel123
View
212
Download
0
Embed Size (px)
DESCRIPTION
Bài giảng về PTHH
Citation preview
CC CNG THC S DNG TRONG PHNG PHP PHN T
HU HN - M HNH CHUYN V - BI TON H THANH
1. Thit lp ma trn cng phn t
1.1 Ma trn cng phn t trong h to a phng
1.1.1 Phn t thanh hai u nt cng (NN)
l
EJ
l
EJ
l
EJ
l
EJl
EJ
l
EJ
l
EJ
l
EJl
EF
l
EFl
EJ
l
EJ
l
EJ
l
EJl
EJ
l
EJ
l
EJ
l
EJl
EF
l
EF
Ke
460
260
6120
6120
0000
260
460
6120
6120
0000
][
22
2323
22
2323
(1)
1.1.2 Phn t thanh u i nt cng, u j khp (NK)
000000
03
033
0
0000
03
033
0
03
033
0
0000
][
323
22
323
l
EJ
l
EJ
l
EJl
EF
l
EFl
EJ
l
EJ
l
EJl
EJ
l
EJ
l
EJl
EF
l
EF
Ke (2)
1.1.3 Phn t thanh u i khp, u j nt cng (KN)
l
EJ
l
EJ
l
EJl
EJ
l
EJ
l
EJl
EF
l
EF
l
EJ
l
EJ
l
EJl
EF
l
EF
Ke
3300
30
3300
30
0000
000000
3300
30
0000
][
22
233
233
(3)
1.2 Ma trn cng phn t trong h to tng th
1.2.1 Ma trn chuyn phng
100000
0cossin000
0sincos000
000100
0000cossin
0000sincos
][
T (4)
1.2.2 Ma trn cng phn t trong h to tng th
]].[.[][]'[ TKTK eT
e (5)
2. Quy i ti trng phn t thnh lc nt tng ng
2.1 Quy i ti trng tc dng trn phn t (theo phng h to a phng) v
thnh lc nt tng ng theo phng h to a phng
2.1.1 Phn t thanh hai u nt cng (NN)
* Do lc phn b u px:
( )
1 1. 0 0 . 0 0
2 2x
T
e x xpR p l p l
(6)
* Do lc phn b u py:
2 2( )
1 1 1 10 . . 0 . .
2 12 2 12y
T
e y y y ypR p l p l p l p l
(7)
* Do ti trng tp trung T:
( )
. .0 0 0 0
T
e T
T b T aR
l l
(8)
* Do ti trng tp trung P:
2 2 2 2
3 2 3 2( )0 ( 2 ) 0 (3 2 )
T
e P
Pb Pab Pa Pa bR l a l a
l l l l
(9)
* Do moment tp trung M:
3 2 3 2( )
6 60 (2 ) 0 (2 )
T
e M
Mab Mb Mab MaR a b b a
l l l l
(10)
2.1.2 Phn t thanh u i nt cng, u j khp (NK)
* Do lc phn b u px:
( )
1 1. 0 0 . 0 0
2 2x
T
e x xpR p l p l
(11)
* Do lc phn b u py:
2( )
5 1 30 . . 0 . 0
8 8 8y
T
e y y ypR p l p l p l
(12)
* Do ti trng tp trung T:
( )
. .0 0 0 0
T
e T
T b T aR
l l
(13)
* Do ti trng tp trung P:
2 2
2 2 2( )0 (3 ) (2 ) 0 (3 ) 0
2 2 2
T
e P
Pb b Pab Pa aR l a
l ll l l
(14)
* Do moment tp trung M:
2 2 2
2 2 2( )
3 30 (1 ) (1 3 ) 0 (1 ) 0
2 2 2
T
e M
M b M b M bR
l ll l l
(15)
2.1.3 Phn t thanh u i khp, u j nt cng (KN)
* Do lc phn b u px:
( )
1 1. 0 0 . 0 0
2 2x
T
e x xpR p l p l
(16)
* Do lc phn b u py:
2( )
3 5 10 . 0 0 . .
8 8 8y
T
e y y ypR p l p l p l
(17)
* Do ti trng tp trung T:
( )
. .0 0 0 0
T
e T
T b T aR
l l
(18)
* Do ti trng tp trung P:
2 2
2 2 2( )0 (3 ) 0 0 (3 ) (2 )
22 2
T
e P
Pb b Pa a PabR l b
l ll l l
(19)
* Do moment tp trung M:
2 2 2
2 2 2( )
3 30 (1 ) 0 0 (1 ) (1 3 )
2 2 2
T
e M
M a M a M aR
l ll l l
(20)
Vect ti trng nt tng ng do ti trng tc dng trn phn t quy i thnh
lc nt tng ng theo phng h to a phng:
( ) ( ) ( ) ( ) ( )x y
e e e e e ep p T P MR R R R R R (21)
2.2 Quy i ti trng tc dng trn phn t (theo phng h to a phng) v
thnh lc nt tng ng theo phng h to tng th:
eT
e RTR .][' (22)
3. Lp ma trn cng tng th, xc nh chuyn v nt, xc nh ni lc:
3.1 Lp ghp:
Ma trn ]'[ eK ca tng phn t ma trn ][ SK .
Vect }'{ eR ca tng phn t vect }'{ SR
Cng vect }'{ SR vi vect ti trng tc dng trc tip ti nt }{ PR vect
lc tng cng ti nt }{ SR
}{}'{}{ PSS RRR (23)
3.2 Xt iu kin bin, kh trng lp:
Ma trn ][ SK ma trn ]*[ sK
Vect }{ SR vect }*{ SR
3.3 Gii h phng trnh: SSS RuK **.*
}*{*}*{ 1 SSS RKu
(24)
3.4 Vect chuyn v nt ca phn t:
Lp ghp cc chuyn v nt (gm nhng chuyn v ti cc lin kt v nhng
chuyn v xc nh t kt qu gii h phng trnh) vect chuyn v nt ca phn t trong
h to tng th eu' .
Vect chuyn v nt ca phn t trong h to a phng eu .
}'{}{ ee uTu (25)
3.5 Vect ni lc ca phn t:
eeee RuKF }{}{ (26)
Ni lc ti 2 u thanh:
)1(ei
FN ; )2(ei
FQ ; )3(ei
FM (27)
)4(ej
FN ; )5(ej
FQ ; )6(ej
FM
1. Ri rc ha kt cu v lp bng s liu:
+ Tin hnh ri rc kt cu thnh 2 phn t v 3 nt.
+ Bng s liu phn t:
Phn t Nt i Nt j E.J E.F l Cos() Sin() Loi PT
1 1 2 2'560 192'000 4 1 0 NN
2 2 3 1'080 144'000 5 0.8 -0.6 NK
+ Bng s liu ti trng trn phn t:
Phn t px py T a b P a b M a b
1 -1.8
2 2.4 2.5 2.5 -3.2 2.5 2.5
+ Bng s liu ti trng tc dng ti nt:
Nt PX PY MZ
2 -5
+ Bng s liu iu kin bin:
Nt uX uY rZ
1 0 0 0
2 0 0 0
3 0 0 khng x
2. Thit lp ma trn cng phn t:
2.1. Phn t 1: (p dng cng thc 1, 4, 5)
Ma trn [Ke]
48'000 0 0 -48'000 0 0
0 480 960 0 -480 960
0 960 2'560 0 -960 1'280
-48'000 0 0 48'000 0 0
0 -480 -960 0 480 -960
0 960 1'280 0 -960 2'560
Ma trn [T]
1 0 0 0 0 0
0 1 0 0 0 0
0 0 1 0 0 0
0 0 0 1 0 0
0 0 0 0 1 0
0 0 0 0 0 1
Ma trn [T]T
1 0 0 0 0 0
0 1 0 0 0 0
0 0 1 0 0 0
0 0 0 1 0 0
0 0 0 0 1 0
0 0 0 0 0 1
K'e (1) (2) (3) (4) (5) (6)
(1) 48'000.0 0.0 0.0 -48'000.0 0.0 0.0
(2) 0.0 480.0 960.0 0.0 -480.0 960.0
(3) 0.0 960.0 2'560.0 0.0 -960.0 1'280.0
(4) -48'000.0 0.0 0.0 48'000.0 0.0 0.0
(5) 0.0 -480.0 -960.0 0.0 480.0 -960.0
(6) 0.0 960.0 1'280.0 0.0 -960.0 2'560.0
2.2. Phn t 2: (p dng cng thc 2, 4, 5)
Ma trn [Ke]
28'800.0 0.0 0.0 -28'800.0 0.0 0.0
0.0 25.9 129.6 0.0 -25.9 0.0
0.0 129.6 648.0 0.0 -129.6 0.0
-28'800.0 0.0 0.0 28'800.0 0.0 0.0
0.0 -25.9 -129.6 0.0 25.9 0.0
0.0 0.0 0.0 0.0 0.0 0.0
Ma trn [T]
0.8 -0.6 0 0 0 0
0.6 0.8 0 0 0 0
0 0 1 0 0 0
0 0 0 0.8 -0.6 0
0 0 0 0.6 0.8 0
0 0 0 0 0 1
Ma trn [T]T
0.8 0.6 0 0 0 0
-0.6 0.8 0 0 0 0
0 0 1 0 0 0
0 0 0 0.8 0.6 0
0 0 0 -0.6 0.8 0
0 0 0 0 0 1
K'e (4) (5) (6) (7) (8) (9)
(4) 18'441.3 -13'811.6 77.8 -18'441.3 13'811.6 0.0
(5) -13'811.6 10'384.6 103.7 13'811.6 -10'384.6 0.0
(6) 77.8 103.7 648.0 -77.8 -103.7 0.0
(7) -18'441.3 13'811.6 -77.8 18'441.3 -13'811.6 0.0
(8) 13'811.6 -10'384.6 -103.7 -13'811.6 10'384.6 0.0
(9) 0.0 0.0 0.0 0.0 0.0 0.0
3. Quy i ti trng phn t thnh lc nt tng ng:
3.1. Phn t 1: (p dng cng thc 7, 21, 22)
( )
0 3.6 2.4 0 3.6 2.4y
T
e pR
0 3.6 2.4 0 3.6 2.4T
eR
T{ 0 3.6 2.4 0 3.6 2.4' }(1) (2) (3) (4) (5) (6)
eR
3.1. Phn t 2: (p dng cng thc 13, 14, 21, 22)
( )
1.2 0 0 1.2 0 0T
e TR
( )
0 2.2 3.0 0 1.0 0T
e PR
1.2 2.2 3.0 1.2 1.0 0T
eR
T{ 0.36 2.48 3.0 0.36 1.52 0' }(4) (5) (6) (7) (8) (9)
eR
4. Lp ma trn cng tng th, xc nh chuyn v nt, xc nh ni lc:
4.1 Lp ghp:
+ Ma trn cng ton h SK :
(1) (2) (3) (4) (5) (6) (7) (8) (9)
(1) 48000.0 0.0 0.0 -48000.0 0.0 0.0 0.0 0.0 0.0
(2) 0.0 480.0 960.0 0.0 -480.0 960.0 0.0 0.0 0.0
(3) 0.0 960.0 2560.0 0.0 -960.0 1280.0 0.0 0.0 0.0
(4) -48000.0 0.0 0.0 66441.3 -13811.6 77.8 -18441.3 13811.6 0.0
(5) 0.0 -480.0 -960.0 -13811.6 10864.6 -856.3 13811.6 -10384.6 0.0
(6) 0.0 960.0 1280.0 77.8 -856.3 3208.0 -77.8 -103.7 0.0
(7) 0.0 0.0 0.0 -18441.3 13811.6 -77.8 18441.3 -13811.6 0.0
(8) 0.0 0.0 0.0 13811.6 -10384.6 -103.7 -13811.6 10384.6 0.0
(9) 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
+ Vect lc nt ton h SR :
- Lp ghp cc vect lc nt do ti trng tc dng trn phn t quy i v nt:
T{ 0 3.6 2.4 0.36 6.08 0.6 0.36 1.52 0' }(1) (2) (3) (4) (5) (6) (7) (8) (9)
SR
- Cng vi lc tc dng trc tip ti nt:
T{ 0 3.6 2.4 0.36 11.08 0.6 0.36 1.52 0 }(1) (2) (3) (4) (5) (6) (7) (8) (9)
SR
4.2 Xt iu kin bin, kh trng lp:
- B cc hng v ct trong ma trn SK c s th t tng ng vi bc t do ca nt c
lin kt, hoc khng xc nh (1, 2, 3, 7, 8, 9) *SK
Ma trn cng [K*]S
66'441.33 -13'811.56 77.76
-13'811.56 10'864.59 -856.32
77.76 -856.32 3'208.00
- B cc hng trong vect SR c s th t tng ng vi bc t do ca nt c lin kt,
hoc khng xc nh (1, 2, 3, 7, 8, 9) *SR
T{ 0.36 11.08 0.6* }(4) (5) (6)
SR
- B cc hng trong vect SR c s th t tng ng vi bc t do ca nt c lin kt,
hoc khng xc nh (1, 2, 3, 7, 8, 9) *SR
4.3 Gii h phng trnh: SSS RuK **.*
}*{*}*{ 1 SSS RKu
Ma trn [K*]-1S
2.0594E-05 2.6702E-05 6.6285E-06
2.6702E-05 0.00012864 3.3692E-05
6.6285E-06 3.3692E-05 0.00032055
T{ 0.0003073 0.0014552 0.000568* }(4) (5) (6)
Su
4.4 Vect chuyn v nt ca phn t:
Lp ghp cc chuyn v nt (gm nhng chuyn v ti cc lin kt v nhng
chuyn v xc nh t kt qu gii h phng trnh) vect chuyn v nt ca phn t trong
h to tng th eu' .
Xc n vect chuyn v nt ca phn t trong h to a phng eu .
{ } { ' }e e eu T u
+ Phn t 1:
T{ 0 0 0 0.0003073 0.0014552 0.000568' }(1) (2) (3) (4) (5) (6)
eu
0 0 0 0.0003073 0.0014552 0.000568T
eu
+ Phn t 2:
T{ 0.0003073 0.0014552 0.000568 0 0 0' }(4) (5) (6) (7) (8) (9)
eu
0.0006273 0.0013485 0.000568 0 0 0T
eu
3.5 Vect ni lc ca phn t:
eeee RuKF }{}{
Ni lc ti 2 u thanh:
)1(ei
FN ; )2(ei
FQ ; )3(ei
FM
)4(ej
FN ; )5(ej
FQ ; )6(ej
FM
+ Phn t 1:
14.748 3.753 3.070 14.748 3.447 2.457T
eF
Ni lc ti 2 u thanh:
14.748iN ; 3.753iQ ; 3.070iM
14.748jN ; 3.447jQ ; 2.457jM
+ Phn t 2:
16.867 2.091 2.457 19.267 1.109 0T
eF
Ni lc ti 2 u thanh:
16.867iN ; 2.091iQ ; 2.457iM
19.267jN ; 1.109jQ ; 0jM