v8.01.110 FDLV110 - Mass calculation added on modes obtained by substructuring

Summary:

This test in the field of modal analysis and fluid-structure interaction uses the calculation of added mass on a structure consisting of three concentric cylinders separated by two fluid rings (water) whose behavior is assumed to be governed by the potential theory (perfect fluid, incompressible at rest). The model is three-dimensional for water. The structure is represented by thin shell elements in modeling A (the structure is rigid in the reference solution). It is characterized by two eigenmodes evaluated by dynamic substructuring, with a CRAIG - BAMPTON interface.

The advantage of the test lies in the use of the “NOEUD_DOUBLE” feature of the “CALC_MATR_AJOU” operator. This feature makes it possible to calculate the effects of added mass of a structure represented by a surface mesh (without thickness) that is immersed in a fluid. The fluids selected in this test case have different densities on either side of the intermediate cylinder (water at different temperatures).

• 1. Reference problem
  • 1.1. Geometry
  • 1.2. Material properties
  • 1.3. Boundary conditions and loads
• 2. Benchmark solution
  • 2.1. Breakdown into substructures
  • 2.2. Calculating the added mass matrix
  • 2.3. Benchmark results
  • 2.4. Bibliographical references
• 3. Modeling A
  • 3.1. Characteristics of modeling
  • 3.2. Tested values
• 4. Summary of results