v8.01.113 FDLV113 - Pressure source in a ball full of fluid interacting with soil - fluid - structure

Summary:

This test contributes to the validation of Code_Aster - MISS3D chaining by the frequency coupling method in soil-fluid-structure interaction (ISFS).

This test makes it possible to consider all types of interfaces: soil-structure, fluid-structure, soil-fluid, free soil. It also makes it possible to test the loading by source of point pressure in the fluid.

It represents a ball, a hollow sphere of finite dimensions, filled with water.

To have all interface types, the lower half of the hollow sphere is modeled by Code_Aster as the « structure » domain; the upper half representing the « ground » domain with the same characteristics as the structure and the « fluid » domain is modeled by MISS3D. A source of harmonic pressure, with a constant unit modulus for each frequency between \(1\mathrm{Hz}\) and \(30\mathrm{Hz}\), is imposed at the center of the ball in the fluid medium.

The modulus of the radial displacements obtained outside and inside the ball is tested with respect to a calculated analytical solution. The agreement is correct provided that the effect of a parasitic resonance corresponding to the first natural frequency of the sphere with mass of water added to the center is suppressed. This is possible by introducing a RFIC parameter in MISS3D.

• 1. Reference problem
  • 1.1. Geometry
  • 1.2. Material properties
  • 1.3. Boundary conditions and mechanical loads
• 2. Benchmark solution
  • 2.1. Benchmark results
  • 2.2. Bibliographical references
• 3. Modeling A
  • 3.1. Characteristics of modeling
  • 3.2. Characteristics of the mesh
  • 3.3. Tested sizes and results
• 4. Summary of results