Page 142 - Finite Element Analysis with ANSYS Workbench

7.4 Application 133

through its Workbench to solve for the natural frequencies and
mode shapes.

We import a CAD file containing the car frame
geometry and construct a finite element model for it. We select
plate bending elements that allow bending together with plane
stress elements for in-plane movement. By using the element size
of approximately 5 cm, the finite element model consists of 10,147
elements and 10,068 nodes as shown in the figure. Since there are
6 unknowns of the three displacements and three rotations at each
node, the problem thus contains the total of 60,408 equations.

Before analyzing the problem, we change the value of
Max Modes to Find under Options in the Details of “Analysis
Setting” window to 10. The software will determine the solutions
up to the first ten modes. Solutions of the first and tenth modes are
shown in the figures.