Chapter 5

ANSYS 命令 : 基礎與觀念Fundamentals and Concepts

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Contents5.1 ANSYS 命令分類

Classification of ANSYS Commands

5.2 準備工作Set Up Commands

5.3 ANSYS 數學式ANSYS Expressions

5.4 座標系統 Coordinate Systems

5.5 模型的元件及選擇 Model Entities and Selections

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第 5.1 節

ANSYS 命令分類Classification of ANSYS Commands

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5.1.1 ANSYS 程序結構...        ! Set up  ...      ! Define parameters

/PREP7     ! Enter preprocessor  ...      ! Build solid model  ...      ! Define attribute tables  ...      ! Generate mesh  FINISH   ! Back to begin level

/SOLU      ! Enter solver  ...      ! Specify loads  ...      ! Specify solution options  ...      ! Solve the model  FINISH   ! Back to begin level

/POST1     ! Enter general postprocessor  ...      ! Read a set of results  ...      ! Plot or print results  FINISH   ! Back to begin level

/POST26    ! Enter time history postprocessor  ...      ! Store solution in variables  ...      ! Plot or print variables

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5.1.2 ANSYS 命令分類

Set Up

Enter/Leave a Module

Parameters and Expressions

Coordinate Systems

Entities Selections

Components

PreprocessingSolid Modeling

Keypoints

Lines

Areas

Volumes

Primitives

Booleans

Element AttributesET Table

MP Table

R Table

CS Table

Attributes Assignment

Mesh GenerationNodes

Elements

Mesh Size/Shape

Auto-Meshing

SolutionLoads

Loads on Analysis Model

Loads on Solid Model

Initial Conditions

Solution Options

Solve

General PostprocessingBasic Commands

Element Tables

Path Operations

Graphics Controls

Time-History Postprocessing

Chapter 5 Chapter 6 Chapter 7

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第 5.2 節

準備工作Set Up Commands

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5.2.1 ANSYS 資料庫與檔案結構

Model

Loads

Result

Jobname.DB

Result at t1

Result at t2

etc.

Jobname.RST

Model

Loads

Result

Database

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5.2.2 Set Up 命令01

02

03

04

05

06

07

FINISH

/CLEAR

/TITLE, Title

/FILNAME, Fname

/SHOW, Fname, Ext

RESUME, Fname, Ext, Dir 

SAVE, Fname, Ext, Dir

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5.2.3 進入與離開模組

01

02

03

04

05

06

07

/PREP7

/SOLU

/POST1

/POST26

/OPT

FINISH

/EXIT

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第 5.3 節

ANSYS 數學式ANSYS Expressions

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5.3.1 ANSYS 數學式01

02

03

04

05

06

07

08

09

10

11

12

13

14

15

16

X=A+B 

P=(R2+R1)/2 

D=-B+(E**2)-(4*A*C) 

XYZ=(A<B)+Y**2 

INC=A1+(31.4/9) 

M=((X2-X1)**2-(Y2-Y1)**2)/2

PI=ACOS(-1) 

Z3=COS(2*THETA)-Z1**2

R2=SQRT(ABS(R1-3))

X=RAND(-24,R2) 

*AFUN,DEG 

THETA=ATAN(SQRT(3)) 

PHI=ATAN2(-SQRT(3),-1) 

*AFUN,RAD 

X249=NX(249) 

SLOPE=(KY(2)-KY(1))/(KX(2)-KX(1))

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5.3.2 參數名稱• Grammatically similar FORTRAN variable

names.• The first 8 letters are significant.• Example of legal names are: ABC, PI,

X_OR_Y.• Examples of illegal names are:

NEW_VALUE, 2CF3, M&E.

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5.3.3 ANSYS 運算符號Operator Description

+ Addition

- Subtraction

* Multiplication

/ Division

** Exponentiation

< Less-than

> Greater-than

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5.3.4 ANSYS 數學函數(FORTRAN-Like Functions)

 ABS(X) SQRT(X) SIN(X) TANH(X)

SIGN(X,Y) NINT(X) COS(X) ASIN(X)

EXP(X) MOD(X,Y) TAN(X) ACOS(X)

LOG(X) RAND(X,Y) SINH(X) ATAN(X)

LOG10(X) GDIS(X,Y) COSH(X) ATAN2(Y,X)

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5.3.5 ANSYS “GET” Functions

Coordinate ID Number DOF Results

NX(N) NODE(X,Y,Z)

UX(N) TEMP(N) ENDS(N)

NY(N) KP(X,Y,Z) UY(N) PRES(N) VOLT(N)

NZ(N) UZ(N) VX(N) MAG(N)

KX(N) ROTX(N) VY(N) AX(N)

KY(N) ROTY(N) VZ(N) AY(N)

KZ(N) ROTZ(N) ENKE(N) AZ(N)

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第 5.4 節

座標系統Coordinate Systems

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5.4.1 為什麼需要座標系統 ?

• When construct a model, you need a CS to refer to.

• For various purpose, more than one CS’s are preferable.

• In ANSYS, CS’s are stored in a CS table.

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5.4.2 Global Coordinate Systems (Predefined CS)

(0) Cartesian (X,Y,Z) (1) Cylindrical (R,q,Z) (2) Spherical (R,q,f) (5) Cylindrical (R,q,Y)

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5.4.3 Local Coordinate System (User-defined CS)

To defined a local CS, you need to specify

• The CS type (e.g., Cartesian)

• Position of origin in global CS

• Directions of the 3 axes

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5.4.4 CS TableID Description

0 Global Cartesian (X,Y,Z)

1 Global Cylindrical (R,,Z)

2 Global Spherical (R,,)

3 (Reserved)

4 Working Plane

5 Global Cylindrical (R,,Y)

6-10 (Reserved)

11 User Defined Local CS

12 User Defined Local CS

… …

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5.4.5 Working Plane

• WP is a predefined CS (no. 4) which is always coincident with the Active CS.

• Many commands are available to manipulate the WP.

• WP can be used as dynamic Local CS.• Primitives are created referring to WP.

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5.4.6 Use of CS’s

• Active CS

• Element CS

• Nodal CS

• Result CS

• Display CS

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5.4.7 CS Table 命令01

02

03

04

LOCAL, KCN, KCS, XC, YC, ZC, THXY, THYZ, THZX

CLOCAL, KCN, KCS, XL, YL, ZL, THXY, THYZ, THZX

CSWPLA, KCN, KCS

CSLIST

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5.4.8 指定座標系統01

02

03

04

05

CSYS, KCN

DSYS, KCN

ESYS, KCN

RSYS, KCN

NROTAT, NODE1, NODE2, NINC

(a) Parallel to global cartesian CS (Default)

(b) Parallel to a local cylindrical CS

(c) Parallel to global cylindrical CS

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5.4.9 Working Plane 命令01

02

03

04

WPCSYS,, KCN

WPOFFS, XOFF, YOFF, ZOFF

WPROTA, THXY, THYZ, THZX

WPLANE,, X, Y, Z, XA, YA, ZA, XP, YP, ZP

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第 5.5 節

模型的元件及選擇Model Entities and Selections

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5.5.1 Model Entities

• Entities to construct a solid model consist of keypoints, lines, areas, and volumes.

• Entities to construct an analysis model consist of nodes and elements.

• The hierarchical relations (from bottom to top) are: keypoints-lines-areas-volumes-nodes-elements.

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5.5.2 Selection of Entities (1/3)

01

02

03

04

05

06

07

NSEL, S, LOC, X, 0

D, ALL, ALL, 0

...

NSEL, ALL

F, N1, FY, -P/2

...

SOLVE

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5.5.2 Selection of Entities (2/3)

NSEL,, LOC, X, 0

NSEL,, LOC, Y, -5, 5

NSEL,, NODE, 1, 100

NSEL, ALL

NLIST, 1, 100

NLIST, ALL

選出 X = 0 的所有節點選出 Y 座標在 -5 至 5 之間的所有節點選出 1 至 100 號的所有節點選出所有定義過的節點以文字列印出 1 至 100 號節點的資料以文字列印出所有節點的資料

NSEL, Type, Item, Comp, VMIN, VMAX, VINC

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5.5.2 Selection of Entities (3/3)

Type Description

S Select a new set (default)

R Reselect a set from the current set

A Select a set and add to the current set

U Unselect a set from the current set

ALL Restore the full set

NONE Clear the current set

INVE Invert the current set; selected becomes unselected and vice versa

STAT Display the current selection status

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5.3.3 Entities Selection Commands01

02

03

04

05

06

07

08

09

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

NSEL, Type, Item, Comp, VMIN, VMAX, VINC

NSLE, Type

NSLK, Type

NSLL, Type, NKEY

NSLA, Type, NKEY

NSLV, Type, NKEY

ESEL, Type, Item, Comp, VMIN, VMAX, VINC

ESLN, Type, EKEY

ESLL, Type

ESLA, Type

ESLV, Type

KSEL, Type, Item, Comp, VMIN,VMAX, VINC

KSLN, Type

KSLL, Type

LSEL, Type, Item, Comp, VMIN, VMAX, VINC

LSLK, Type, LSKEY

LSLA, Type

ASEL, Type, Item, Comp, VMIN, VMAX, VINC

ASLL, Type, ARKEY

ASLV, Type

VSEL, Type, Item, Comp, VMIN, VMAX, VINC

VSLA, Type, VLKEY 

DOFSEL, Type, Dof1, Dof2, ..., Dof6

ALLSEL

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5.5.4 Components

01

02

03

04

CM, Cname, Entity

CMGRP, Aname, Cname1, Cname2, ..., Cname8

CMSEL, Type, Name

CMLIST, Name