v2.02.158 SDLL158 — Validation of beam modal parameters

Summary:

The problem consists in validating the modal parameters calculated on a modal basis of the mode_meca type resulting from a concept of the mode_gene type, in comparison with a direct calculation. For this, the natural modes of a beam are calculated by a direct calculation, and by an orthogonalized Ritz base using a mode_gene concept.

The Ritz base is calculated using the Craig-Bampton method: The natural modes are calculated with additional blocks, then the modal base is enriched with static bearings to release these blockages. This modal base is then orthogonalized by calculating the generalized modes in order to reveal the natural modes calculated without these blockages. Two problems are present, with and without rigid body modes.

This test case makes it possible to validate the frequencies, effective masses, and participation factors from an orthogonalized Ritz base using generalized modes.

• 1. Reference problem
  • 1.1. Geometry
  • 1.2. Material properties
  • 1.3. Boundary conditions and loads
• 2. Benchmark solution
  • 2.1. Calculation method used for the reference solution
  • 2.2. Benchmark results
• 3. Modeling A
  • 3.1. Characteristics of modeling
  • 3.2. notes
  • 3.3. Tested sizes and results
• 4. B modeling
  • 4.1. Characteristics of modeling
  • 4.2. notes
  • 4.3. Tested sizes and results
• 5. Summary of results