Chapter 12 連桿與桁架結構分析 Analysis of Links and Trusses

2/29 Contents 12.1LINK1: 2D 連桿元素 LINK1: 2D Link Element 12.2 實例 : 桁架設計 Example: Analysis of a Truss Structure 12.3 實例 : 超靜定柱子之反力計算 Example: Statically Indeterminate Reaction Force Analysis 12.4 實例 : 熱應力計算 Example: Thermally Loaded Support Structure 12.5 連桿元素瀏覽 Overview of Link Elements 12.6 練習題 Exercises

3/29 第 12.1 節 LINK1: 2D 連桿元素 LINK1: 2D Link Element

4/ LINK1 元素描述

5/ LINK1 輸入資料 Element NameLINK1 NodesI, J Degrees of FreedomUX, UY Real ConstantsAREA, ISTRN Material PropertiesEX, ALPX, DENS, DAMP Surface LoadsNone Body LoadsTemperature -- T(I), T(J) Special FeaturesPlasticity, Creep, Stress stiffening, Large deflection

6/ LINK1 輸出資料

7/29 第 12.2 節 實例 : 桁架設計 Example: Analysis of a Truss Structure

8/ 問題描述 lb Unit of dimension: in. Material: Steel All section areas = 5 in 2

9/ ANSYS Procedure (1/3) FINISH /CLEAR /UNITS, BIN YOUNG = 29E6 ! Young’s modulus AREA = 5 ! Cross-sectional area LOAD = 5000 ! Design load /PREP7 ET, 1, LINK1 MP, EX, 1, YOUNG R, 1, AREA

10/ ANSYS Procedure (2/3) N, 1, 0, 0 N, 2, 180, 0 N, 3, 0, 180 N, 4, 180, 180 N, 5, 30, 300 N, 6, 150, 300 N, 7, 30, 420 N, 8, 150, 420 N, 9, -90, 480 N, 10, 270, 480 N, 11, -210, 540 N, 12, -90, 540 N, 13, 30, 540 N, 14, 150, 540 N, 15, 270, 540 N, 16, 390, 540 EN, 1, 1, 2 EN, 2, 3, 4 EN, 3, 5, 6 EN, 4, 7, 8 EN, 5, 11, 12 EN, 6, 12, 13 EN, 7, 13, EN, 8, 14, 15 EN, 9, 15, 16 EN, 10, 1, 3 EN, 11, 2, 4 EN, 12, 3, 5 EN, 13, 4, 6 EN, 14, 5, 7 EN, 15, 6, 8 EN, 16, 7, 9 EN, 17, 8, 10 EN, 18, 9, 11 EN, 19, 10, 16 EN, 20, 9, 12 EN, 21, 7, 13 EN, 22, 8, 14 EN, 23, 10, 15 EN, 24, 1, 4 EN, 25, 4, 5 EN, 26, 5, 8 EN, 27, 9, 13 EN, 28, 8, 13 EN, 29, 10, 14 FINISH

11/ ANSYS Procedure (3/3) /SOLU D, 1, UY, 0 D, 2, UX, 0 D, 2, UY, 0 F, 11, FY, -LOAD F, 16, FY, -LOAD /PNUM, NODE, 1 /PNUM, ELEM, 1 /PBC, ALL,, 1 EPLOT SOLVE FINISH /POST1 PLDISP, 2 ETABLE, MFORCE, SMISC, 1 ETABLE, STRESS, LS, 1 ETABLE, STRAIN, LEPEL, 1 PRETAB, MFORCE, STRESS, STRAIN

12/29 第 12.3 節 實例 : 超靜定柱子之反力計算 Example: Statically Indeterminate Reaction Force Analysis

13/ 問題描述

14/ ANSYS Procedure (1/2) FINISH /CLEAR /UNITS, BIN /PREP7 ET, 1, LINK1 R, 1, 1 MP, EX, 1, 30E6 N, 1, 0 0 N, 2, 0, 4 N, 3, 0, 7 N, 4, 0, 10 E, 1, 2 E, 2, 3 E, 3, 4 FINISH

15/ ANSYS Procedure (2/2) /SOLU D, 1, ALL, 0 D, 4, ALL, 0 F, 2, FY, -500 F, 3, FY, /PNUM, NODE, 1 /PNUM, ELEM, 1 /PBC, ALL,, 1 EPLOT SOLVE FINISH /POST1 PRRSOL

16/29 第 12.4 節 實例 : 熱應力計算 Example: Thermally Loaded Support Structure

17/ 問題描述

18/ ANSYS Procedure (1/2) FINISH /CLEAR /UNITS, BIN /PREP7 ET, 1, LINK1 R, 1,.1 MP, EX, 1, 16E6 MP, ALPX, 1, 9.2E-6 MP, EX, 2, 30E6 MP, ALPX, 2, 7.0E-6 N, 1, -10, 0 N, 3, 10, 0 FILL N, 4, -10, -20 N, 6, 10, -20 FILL E, 1, 4 E, 3, 6 MAT, 2 E, 2, 5 CP, 1, UY, 5, 4, 6 FINISH

19/ ANSYS Procedure (2/2) /SOLU D, 1, ALL, 0,, 3, 1 F, 5, FY, TREF, 70 BFUNIF, TEMP, 80 /PNUM, NODE, 1 /PNUM, ELEM, 1 /PBC, ALL,, 1 EPLOT SOLVE FINISH /POST1 ETABLE, STRESS, LS, 1 PRETAB, STRESS

20/29 第 12.5 節 連桿元素瀏覽 Overview of Link Elements

21/ General Structural Links

22/ Finite Strain Link

23/ Tension-Only Structural Link

24/ Explicit Dynamics

25/ Conduction Links

26/ Convection Link

27/ Radiation Link

28/ Coupled-Field Link

29/29 第 12.6 節 練習題 Exercises