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From CAD to CAE (1-ANSYS) 11/22/2008. Basics of FEA. Finite Element Element with finite volume/area and finite number Major Steps: a) Pre-Process Geometry/mesh b) Solve Load/B.C/I.C c) Prost-Process List/plot results. Pre-setup.
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From CAD to CAE (1-ANSYS) 11/22/2008
Basics of FEA Finite Element Element with finite volume/area and finite number Major Steps: a) Pre-Process Geometry/mesh b) Solve Load/B.C/I.C c) Prost-Process List/plot results
Pre-setup • GGUI: Utility Menu > File > Change Jobname > 輸入 chair • GGUI: Utility Menu > File > Change Title >輸入 chair • GGUI: Main Menu > Preferences > Structural 打勾
CAD/CAE systemData exchange CAD Pro/E Solid Edge Solid Works UG I-Deas … CAE ANSYS COMSOL MSC.MARC MSC.Nastran ABAQUS Moldex Mold Flow … Iges Stl Parasolid …
IGES, Parasolid, STL • IGES=Initial Graphics Exchange Specification • 轉檔缺點: 常有破洞, 尤其CAD曲面 • 轉檔失敗機率: 不一定 • 對策: • 1.修補 • 2.改CAD的特徵 • 3.換其他轉檔格式(*.x_t , *.SAT …), 但注意軟體是否支援, 是否付費 • 以CAD軟體來畫外形: 省時省力 Para: Stl:
Import CAD Model • GUI: Utility Menu > File > Import > IGES/Para > 找到IGES/Para檔案的目錄 讀入 chairansys.iges/Para
Import IGES (續) • GUI: Utility Menu > PlotCtrls > Style > Solid Model Facets > • GUI: Utility Menu > List > Volumes • GUI: Utility Menu > Plot > Volumes
Define Element ANSYS手冊
Define Material SI Unit: mm , N, MPa
Mesh Tool: Volume free mesh • GUI: Main Menu > Preprocessor > Meshing > Mesh Tool
Mesh Result Try to plot points/nodes/lines/areas/elements
Boundary Conditions • GUI : Main Menu > Solution > Analysis Type > New Analysis > Static • GUI : Main Menu > Solution > Define Loads > Apply > Structural > Displacement UX=0 對稱面 UZ=0 對稱面 UY=0 線
Boundary Conditions UX=0 對稱面
Apply Pressure • GUI : Main Menu > Solution > Define Loads > Apply > Structural > Pressure 0.2 MPa = 200,000 N/m^2
Apply Pressure 0.2 MPa = 200,000 N/m^2
Apply Pressure 0.2 MPa = 200,000 N/m^2
Save *.db • GUI: Utility Menu > File > Save as Jobname.db , • in your working directory
Solution • GUI: Main Menu > Solution > Solve > Current LS >
討 論 • FEM model 準不準確? • 以CAE分析來說, 此“類似塑膠椅”的結構還要考慮什麼? • 強度夠不夠? • 可載重多大? • CAD 之 IGES檔案, 使用上的優缺點.