4--网格划分.doc

W9.3IntroductionIn this workshop you will use the Mesh module of ABAQUS/CAE to generate the finite element meshes for the pump assembly model. The required tasks include assigning mesh attributes to each part instance, assigning mesh seeds, and generating the meshes.Modifying the pump housing element type1. Open the model database file PumpAssy.cae. Switch to the Mesh module; and, from the context bar, select pump_ribs from the list of available models.2. Use the assembly display options (ViewAssembly Display Options) to suppress the visibility of all part instances save for the pump housing. In addition, suppress the visibility of all datum planes and axes.3. ABAQUS 4. Next, create a set that includes all the elements comprising the pump housing. From the main menu bar, select ToolsSetCreate. 5. In the Create Set dialog box, select Element as the set type. Name the set pump-mesh and click Continue. 6. Select all the elements in pump housing using a rectangular drag window. Use the selection filters if necessary. Click Done when the selection is complete.Use the Query tools to determine the type of element currently assigned to the mesh. 7. From the main menu bar, select ToolsQuery. The Query dialog box appears. 8. From the list of available General Queries, select Element and click Apply. Click on any element and note that the elements label, type, and nodal connectivity are listed in the message area, as shown in Figure W91. Repeat this for other elements in the mesh. Figure W91. Selected element attributes9. Click Cancel in the Query dialog box to close it. 10. The element type for the pump housing is the linear tetrahedron (C3D4), which is not suited for an analysis involving contact. Thus, change the element type assigned to the pump housing to modified second order tetrahedrons (C3D10M). 11. From the main menu bar, select MeshElement Type.12. When prompted for the type of region, click Sets on the right side of the prompt area.13. The Region Selection dialog box appears. Select the set pump-mesh and click Continue.14. The Element Type dialog box appears. Review the current settings. Toggle on Quadratic under Geometric Order. Notice that the element type message changes to C3D10M. Click OK.15. Use the Query tools to confirm that the element type associated with the mesh has been updated.Generating the bolt meshUse the assembly display options to restore the visibility of the bolts and suppress the visibility of the pump housing. The bolts are colored yellow, indicating they can be readily meshed with hexahedral elements using a swept mesh technique. Mesh the bolts with a local edge seed of 8 using first-order incompatible mode hexahedral elements (C3D8I). 1. From the main menu bar, select SeedEdge by Number.2. Select all the edges of the bolts using a rectangular drag window.3. When prompted for the number of elements along the edges, enter 8.4. From the main menu bar, select MeshElement Type to change the element type associated with the bolts.Tip: Click Select in Viewport on the right side of the prompt area to select the bolts directly in the viewport.5. In the prompt area, select Geometry as the region type. Using a rectangular drag shape, select all the bolts. 6. In the Element Type dialog box, choose Incompatible modes under Element Controls. Click OK.7. From the main menu bar, select MeshInstance to mesh the bolts. Click one of the bolts when prompted for the instance to be meshed.8. Review the mesh when the operation is complete. The mesh of one of the bolts is shown in Figure W92.Generating the cover and gasket meshesThe CoverUse the assembly display options to restore the visibility of the cover and suppress the visibility of the bolts. The cover is colored orange, indicating that it cannot be meshed with hexahedral elements without the aid of partitioning. For the purpose of this exercise, mesh the cover using the free tetrahedral mesh technique. Use a global seed size of 0.35 and element type C3D10M.1. From the main menu bar, select MeshControls. Select the cover as the region to which mesh controls will be assigned; and, in the Mesh Controls dialog box, select Tet as the element shape. Click OK to continue.The part is now colored pink, indicating it can be meshed with the free mesh technique.2. Assign a global mesh seed size (SeedInstance) of 0.35 and local edge seeds (SeedEdge By Number) of 8 to the edges comprising the bolt holes.3. From the main menu bar, select MeshElement type. Select the cover geometry as the region to which the element type will be assigned and choose the modified quadratic tetrahedron element type (C3D10M).4. Generate the cover mesh. The mesh on the cover plate is shown in Figure W92.The GasketUse the assembly display options to restore the visibility of the gasket and suppress the visibility of the cover. The gasket is colored yellow, indicating it can be readily meshed with hexahedral elements using a swept mesh technique. 1. Assign a global mesh seed size (SeedInstance) of 0.25.2. Assign the linear hexahedral gasket element type (GK3D8) to the g