Normal Modes Solution in Simcenter 3D: A Quick Setup Note

This is the step list I use to quickly get the natural frequencies of a part in Simcenter 3D. For the detailed theory, see the modal analysis article; the goal here is practical setup.

Steps#

1. Create a new FEM and Simulation file. Prepare the idealized geometry on the FEM side.
2. Assign material — make sure density is defined; the modal solution needs mass.
3. Mesh — enough elements through the thickness; prefer second-order tetrahedra.
4. Create a solution → Solution Type: SOL 103 Real Eigenvalues.
5. Choose the Lanczos method and enter the desired number of modes or a frequency range.
6. Apply boundary conditions if needed. For free-free, apply no constraints.
7. Solve and inspect the natural frequencies + mode shapes in the results.

A Common Mistake#

Forgetting density. If a material carried over from a static analysis has no density defined, the modal solution returns meaningless results or an error. Always check the material card first.