Page 170 - Finite Element Modeling and Simulations with ANSYS Workbench

Two-Dimensional Elasticity 155

Double-click on the Geometry cell in Project Schematic to launch SpaceClaim.
For the imported wrench model, set Millimeters as the unit for Length in
SpaceClaim Options. Next, click on the Surface item in the Structure Tree, and
enter 3 for Thickness in the lower left Properties panel. Close SpaceClaim, and
double-click on the Model cell in the Project Schematic to launch the Static
Structural program. A wrench surface is now ready for plane stress analysis.

4.6 Summary

The 2-D elasticity equations are reviewed in this chapter and 2-D elements for analyzing
plane stress and plane strain problems are discussed. FE formulations for 2-D stress analy-
sis are introduced. It is emphasized that linear triangular (T3) and linear quadrilateral (Q4)
elements are good for deformation analysis and not accurate for stress analysis. For stress
analysis, quadratic triangular (T6) and quadratic quadrilateral (Q8) elements are recom-
mended. Bad-shaped elements with large aspect ratios and large or small angles should
be avoided in an FE mesh. A wrench model is built and the stress is analyzed in ANSYS
Workbench to show how to conduct a 2-D FEA.

4.7 Review of Learning Objectives

Now that you have finished this chapter you should be able to
1. Develop the FE formulations for 2-D stress analysis problems.
2. Create a mesh for a 2-D stress analysis problem and be able to judge the mesh quality.