Page 270 - Finite Element Modeling and Simulations with ANSYS Workbench

Three-Dimensional Elasticity 255

Right-click on Static Structural (A5) and select Solve. Click on the deformation
and stress results under Solution (A6) and compare them with results from
the full model.

7.6 Summary

In this chapter, we discussed the 3-D solid elements for elasticity problems, that is, general
3-D deformation and stress analyses. Solid elements are the most accurate elements and
should be applied when the bar, beam, plane stress/strain, and plate/shell elements are no
longer valid or accurate. For stress concentration problems, higher-order solid elements,
such as 10-node tetrahedron or 20-node hexahedron (brick) elements, should be employed
in the FEA. For solids having symmetrical features, symmetric FEA models can be more
effective and efficient.

7.7 Review of Learning Objectives

Now that you have finished this chapter you should be able to

1. Understand the FE formulations for 3-D stress analysis
2. Know the behaviors of the 3-D (tetrahedron and hexahedron) elements
3. Create quality mesh over solids for 3-D stress analysis
4. Perform detailed stress analysis of 3-D structures using ANSYS Workbench

PROBLEMS
7.1 For a tapered bar shown below, study the deformation and stresses in the bar
with a 3-D model using solid elements and a 1-D model using 1-D bar ele-
ments. Assume R = 1 m, R = 0.5 m, L = 5 m, force F = 3000 N, Young’s modulus
2
1