ANSYS结构静力学分析应用实例解析--钢桁架桥的受力分析

1. 问题描述

钢桁架桥简图如下，已知下承式简⽀钢桁架桥长72m，每个节段为12m，桥宽10m，⾼16m。设桥⾯板为0.3m厚的混凝⼟板。

2. 求解步骤

2.1 建⽴⼯作⽂件名和⼯作标题/FILNAME,Structural

/TITLE,Truss Bridge Static Analysis2.2 过滤图形界⾯

/COM, Structural ! 指定分析类型为结构分析2.3 定义单元类型/PREP7ET,1,BEAM4ET,2,SHELL632.4 定义梁单元截⾯

Main Menu>Preprocessor>Sections>Beam>Common Sections

SECTYPE,1,BEAM,I, , 0 ! 定义⼯字型截⾯ SECOFFSET, CENT ！截⾯质⼼不偏移SECDATA,0.4,0.4,0.4,0.016,0.016,0.016,0,0,0,0 ！定义⼯字型截⾯参数SECTYPE,2,BEAM,I, , 0 ! 定义⼯字型截⾯SECOFFSET, CENT ！截⾯质⼼不偏移

SECDATA,0.4,0.4,0.4,0.012,0.012,0.012,0,0,0,0 ！定义⼯字型截⾯参数SECTYPE,3,BEAM,I, , 0 ! 定义⼯字型截⾯SECOFFSET, CENT ！截⾯质⼼不偏移

SECDATA,0.3,0.3,0.4,0.012,0.012,0.012,0,0,0,0 ！定义⼯字型截⾯参数2.5 定义实常数Main Menu>Preprocessor>Real Constants>Add/Edit/Delete

R,1,0.0187,0.00017,0.00054,0.4,0.4, , ！定义单元实常数

R,2,0.0141,0.128E-3,0.415E-3,0.4,0.4R,3,0.0117,0.541E-4,0.324E-3,0.3,0.4R,4,0.3

2.6 定义材料属性

MP,EX,1,2.1E11 ! 定义钢材的材料属性MP,PRXY,1,0.3MP,DENS,1,7800

MP,EX,2,3.5E10 ! 定义混凝⼟的材料属性MP,PRXY,2,0.1667MP,DENS,2,25002.7 创建有限元模型2.7.1 ⽣成半跨桥的节点

N,,0,0,-5

NGEN,4,4,ALL,,,12,,,1NGEN,2,1,ALL,,,,,10,1NGEN,2,1,2,10,4,,16,,1NGEN,2,1,3,11,4,,,-10,12.7.2 ⽣成半跨桥单元TYPE,1MAT,1REAL,1ESYS,0

SECNUM,1 ！选择截⾯编号TSHAP,LINE !选择线性单元E,11,14E,12,13

TYPE,1MAT,1REAL,2ESYS,0

SECNUM,2 ！选择截⾯编号TSHAP,LINE !选择线性单元E,2,6E,6,10E,10,14E,1,5E,5,9E,9,13

E,3,7E,7,11E,4,8E,8,12E,1,2E,3,4E,5,6E,7,8E,9,10E,11,12E,13,14

TYPE,1MAT,1REAL,3ESYS,0

SECNUM,3 ！选择截⾯编号TSHAP,LINE !选择线性单元E,3,6E,6,11E,4,5E,5,12E,2,3E,1,4E,6,7E,5,8E,10,11E,9,12

TYPE,2MAT,2REAL,4ESYS,0

SECNUM,3 ！选择截⾯编号TSHAP,QUAD !选择四边形单元E,1,2,6,5E,5,6,10,9E,9,10,14,13

Main Menu>Preprocessor>Modeling>Reflect>Nodes

NSYM,X,14,ALL ! 所有节点以YOZ 平⾯对称

ESYM,,14,ALL ！所有单元以YOZ 平⾯对称2.7.4 合并重合节点和单元

NUMMRG,ALL,,,,LOW ! 合并重复节点单元，编号取较⼩者NUMCMP,ALL ! 压缩节点单元等编号

2.7.5 保存模型并退出前处理器SA VE,’mo_xing’,’db’FINISH

2.8 施加位移约束/SOL

2.8.1 施加位移约束

NSEL,S,,,23,24 ! 选择左端节点

D,ALL,,,,,,UX,UY,UZ ! 对左端节点施加位移约束NSEL,S,,,13,14 ! 选择右端节点

D,ALL,,,,,,UY,UZ ! 对右端节点施加位移约束2.8.2 施加集中⼒

NSEL,S,,,1,2 ! 选择中间节点

F,ALL,FY,-100000 ! 对中间节点施加竖向集中⼒荷载2.8.3 施加重⼒ALLSEL,ALL

ACEL,0,10,0 ! 施加重⼒

2.9 求解计算ANTYPE,0SOLVEFINISH

2.10 查看计算结果2.10.1 查看结构变形图/POST1

PLDISP,2 ! 显⽰结构变形图

2.10.2 云图显⽰位移PLNSOL,U,SUM,0,1 ! 显⽰总位移云图

Main Menu>General Postproc>Plot Results>Vector Plot>Predefined

PLVECT,U,,,,VECT,NODE,ON,0 ! 显⽰节点总位移⽮量图

2.10.4 显⽰结构内⼒图2.10.4.1 定义单元表

Main Menu>General Postproc>Element Table>Define Table

ETABLE,zhouli_i,SMISC,1 ! 定义单元表轴⼒ETABLE,zhouli_j,SMISC,7

ETABLE,jianli_i,SMISC,2 ! 定义单元表剪⼒ETABLE,jianli_j,SMISC,8

ETABLE,wanju_i,SMISC,6 ! 定义单元表弯矩ETABLE,wanju_j,SMISC,122.10.4.2 列表单元表结果

PRETAB, zhouli_i, zhouli_j, jianli_i, jianli_j, wanju_i, wanju_j ! 列表显⽰单元表结果

Main Menu>General Postproc>Plot Results>Contour Plot>Line Elem Res

PLLS, zhouli_i, zhouli_j,1,0 ! 显⽰轴⼒图