New 102-line test file for modal elasticity analysis:
- Tests modal analysis of long rod with fixed-fixed boundary conditions
- Compares eigenfrequencies with Code Aster results (Tet10 elements)
- Validates against analytical solution (fixed-fixed beam)
- Tests 5 lowest eigenfrequencies
- Uses legacy Element/Problem API
Validates modal analysis accuracy by comparing with reference
Code Aster results and analytical beam theory.
Jukka Aho