v5.02.138 SDNL138 - Frequencies and natural modes of vibration of a self-stressed frame

Summary:

The objective of this test is to validate the calculation of the vibration frequencies and modes of vibration of a self-stressed frame. The forces in the structure are only generated by the tension of the cables. The principle of the test case is to:

• perform a non-linear calculation,

• retrieve the various fields at a given moment,

• calculate stiffness and mass matrices,

• calculate vibration frequencies and modes.

Several models are carried out:

• calculation with STAT_NON_LINE, use of operators CALC_MATR_ELEM, ASSE_MATRICE and COMB_MATR_ASSE for assembling matrices. Then calculate the frequencies and vibration modes with operator CALC_MODES.

• calculation with DYNA_NON_LINE and option MODE_VIBR.

• calculation with STAT_NON_LINE, determination of the stiffness matrix using the CALCUL operator. Then calculate the frequencies and vibration modes with operator CALC_MODES.

The results are compared to a theoretical solution.

• 1. Reference problem
  • 1.1. Geometry
  • 1.2. Material properties
  • 1.3. Mechanical characteristics
  • 1.4. Boundary conditions and loads
  • 1.5. Initial conditions
• 2. Benchmark solution
  • 2.1. Calculation method
  • 2.2. Reference quantities and results
  • 2.3. Uncertainties about the solution
• 3. Modeling A
  • 3.1. Characteristics of modeling
  • 3.2. Characteristics of the mesh
  • 3.3. Tested sizes and results
  • 3.4. notes
• 4. B modeling
  • 4.1. Characteristics of modeling
  • 4.2. Characteristics of the mesh
  • 4.3. Tested sizes and results
  • 4.4. notes
• 5. C modeling
  • 5.1. Characteristics of modeling
  • 5.2. Characteristics of the mesh
  • 5.3. Tested sizes and results
  • 5.4. notes
• 6. Summary of results