Femap基础培训四面体网格与六面体网格Exercise 10 Tet vs Hex Meshing

Introduction

In this example we will explore two different representations of the same model. One is comprised of Tetrahedral elements, and the other, composed of Hexahedral elements. This exercise is comprised of the following steps:

•Import the Parasolid geometry of the bracket

•Apply Loads and Constraints to the Bracket

•Mesh the part with Tetrahedral Solid Elements

•Setup and run an Analysis on the Bracket

•Prepare the model for re-meshing with Solid Hex Elements The preferences and units used in this exercise are:

Solid Geometry Scale Factor:Inches

Force:lbf

Pressure:psi

Density:lbm/ in3

Step 1:Import Parasolid geometry

Set your Femap preference for the Geometry Scale Factor to inches.

•Open the Preferences dialog box with the File, Preferences command

Select the Geometry/Model tab.

Set the Solid Geometry Scale Factor to 0..Inches.

Import the Geometry from the class Geometry folder •Select the command, File, Import, Geometry and choose the file Ge0metry\Ex10 -Bracket.x_t from the class files folder.

•Accept the defaults in the Solid Model Read Options dialog box by clicking OK.

Rotate the view.

•Rotate the model into the position shown here by clicking the left mouse button, and holding it while dragging the

mouse.

Step 2:

Apply Loads and Constraints to the Bracket •Select the Model, Load, On Surface command or use the Create Load on Surface icon on the Load toolbar.

Type in a descriptive title for the Load Set, e.g. “Vertical load on boss ” and click OK to create the load set.

When the entity selection box appears, select the

highlighted surface. Use the Preview Selection icon if needed to display the selected surface before confirming your selection.

•Click OK to confirm your selection

Complete applying the load to the surface.

•In the Create Load on Surfaces dialog box, enter the Title as 20000 lb Vertical Load.

•Select Force as the load type

•Set FZ to 2e4(20000).

•Click OK to create the load.

•Click Cancel or the esc key to exit the command.

Save your model.

•Save the model in your Exercises folder as ex10-

TetMesh.modfem.

Create “fixed” geometric constraints on the inside of the bracket.

•Select the Model, Constraint, On Surface command or use the Create Constraint on Surface icon on the Constraint

toolbar.

•Enter a descriptive title for the Constraint Set. Click OK to create it.

•Select the two inside surfaces of the bracket and confirm the selection by clicking OK.

•Enter a descriptive Title for the constraint.

•Select Fixed in the Standard Types section and click OK to create the constraint.

•Click Cancel or the esc key to exit the command.