汽车结构有限元分析第四讲有限元程序应用介绍

1、第四讲 有限元程序应用介绍,-ANSYS程序介绍与上机操作 合肥工业大学机械与汽车学院 2010年2月,1.有限元软件前处理,前处理建模菜单 ：Preprocessor Element Type Add/Edit/Delete Structural (Mass, Link, Beam, Pipe, Solid, Shell) Constraint (MPC) Contact Combination (Spring-damper, Combination, Revolute) Superelement Real Constants Material Properties Material Lib

2、rary Material Models: Structural: Linear: Elastic Nonlinear: Elastic, Inelastic, Rate Independent, Rate Dependent Density Damping Friction Coefficient Sections Section Library, Beam, Shell, Joints,前处理建模菜单 ：Preprocessor- Modeling,Create: Keypoints Lines (Lines, Arcs, Splines, Line Fillet) Areas (Arbi

3、trary, Rectangle, Circle,Polygon, Area Fillet) Volumes (Arbitrary, Block, Cylinder, Prism, Sphere, Cone) Nodes (Write /Read Node File) Elements (Write /Read Node File, Superelements) Operate: Extrude (Keypoints, Lines, Areas) Booleans (Intersect, Add, Subtract, Divide, Glue, Overlap) Scale (Keypoint

4、s, Lines, Areas, Volumes, Nodes) Calc Geom Items (Keypoints, Lines, Areas, Volumes) Move/Modify: Keypoints, Lines, Areas, Volumes, Nodes, Elements Rotate Node CS Transfer Coordinate Reverse Normals Copy：Keypoints, Lines(Mesh), Areas(Mesh), Volumes, Nodes, Elements Reflect：Keypoints, Lines, Areas, Vo

5、lumes, Nodes, Elements Check Geom:Select Small Lines, Show Degeneracy, KP distance , ND distance Delete:Keypoints, Lines, Areas, Volumes, Nodes, Elements,前处理建模菜单 ：Preprocessor- Meshing,Mesh Attributes: Element type number Material number Real constant set number Element coordinate system Mesh Tool:

6、Element Attributes Set Smart Size (Fine, Coarse) Size Controls (Keypoints, Lines, Areas, Global) Mesh (Keypoints, Lines, Areas, Volumes) Shape (Tet, Hex,Tri, Quad, Free, Mapped, Sweep) Size Controls: Smart Size, Manual Size, Concentrate Keypoints Modify Mesh: Refine, Improve Check Mesh: Individual E

7、lement (Plot Bad Element), Connectivity Clear: Keypoints, Lines, Areas, Volumes,前处理建模菜单 ：Preprocessor- Checking Controls,Model Checking: Model/FEA Checking Shape Checking: Level of shape checking Toggle Checks: Aspect Ration Tests Shear/Twist Angle Deviation Tests Parallel Side Tests Maximum Angle T

8、ests Jacobian Ration Tests Warp Tests Numbering Controls Merge Items： Nodes, Elements, Keypoints Compress Numbers: Nodes, Elements, Keypoints, Lines, Areas, Volumes Coupling/Constraint Equation Couple DOFs, Coincident Nodes, Constraint Equation, Rigid Region Loads Analysis Type: Static, Modal, Harmo

9、nic, Transient, Spectrum, Eigen Buckling, Substructure Define Loads:,结构单元类型： 主要有杆单元、梁单元、管单元、平面单元、三维实体单元、壳单元、接触单元、特殊单元（质量单元、弹簧单元、表面单元、多点约束）、显式动力学单元等。在实际使用时要注意查阅单元手册，了解单元属性，正确选用单元。,结构分析类型，主要有七个方面： 静态分析; 模态分析; 谐响应分析; 瞬态动力学分析; 谱分析; 屈曲分析; 子结构分析; 其它还有断裂力学问题、复合材料问题、疲劳分析、显式动力学分析等也属结构分析范围。,按照有限元软件前处理功能，建模工作可

10、概括为下述几个方面：,建立几何模型 建立有限元模型与网格划分 施加载荷及边界条件,2.有限元软件计算 -Solution,Analysis Type: Static Modal Harmonic Transient Spectrum Eigen Buckling, Substructure Solution Controls Basic Analysis Options: Small Displacement Static Large Displacement Static Small Displacement Transient Large Displacement Transient Ti

11、me Control (Number of Substeps, Time increment) Transient Full Transient Options Damping Coefficients Middle Step Criterion,-Solution,Solution Options Equation Solvers: Program chosen solver Sparse direct Pre-Condition CG Iterative Frontal direct Nonliner Nonlinear Option: Line search DOF solution p

12、redictor Equilibrium Iterations Creep Option,-Solution,Define Loads: Settings Apply Displacement Force/Moment Temperature Gravity Initial Condition Delete (Loads) Load Step Options: Output Controls Solution Print out, Grophical Solution Tracking, PGR file, Intergration Points Other : Birth & Death,

13、User Routines Read / Write Load Case File Initial Stress Solve Current Load Case From Load Case Files,3.有限元软件后处理 -General Postprocessor,Data & File Options Results Summary Read Results: First set, Next set, By Load Step, By Time/Freq, By Set Number Plot Results:Deformed Shape, Contour Plot, Vector Plot, Plot Path Item List Results:Nodal Solution, Element Solution, Iteration Summary Query Results:Element Solution, Subgrid Solution Nodal Calculations:Total Force Sum, Summation Element Table:Define Table, Plot Element Table Path Operations:Define Path, Plot Path Item Load Case Check