5. C modeling#

5.1. Characteristics of modeling#

The eigenmodes of the complete system are calculated using the modal calculation method by substructuring with “Craig-Bampton” interfaces (blocked interfaces). The bases of each substructure are composed of a dynamic mode and a constrained mode.

The dynamic mode of each substructure is associated with a damping reduced by \(\text{1\%}\).

The transient response of the damped system is calculated on the modal basis calculated by substructuring.

The time steps taken are equal to: \({10}^{-2}s\) in EULER, \({10}^{-2}s\) in NEWMARK, in, \({10}^{-2}s\) in ADAPT_ORDRE2 (for the latter, this is the initial time step of the algorithm and the maximum time step is set to the formula \(\mathrm{0,1}s\) to optimize the calculation time).

5.2. Characteristics of the substructure mesh#

Number of knots: 3

Number of meshes and types: 2 SEG2

5.3. Tested sizes and results#

Identification

Reference

Method: EULER

Node \({x}_{2}\), move (\(m\))

4.9867 10—1

Method: NEWMARK

Node \({x}_{2}\), move (\(m\))

4.9867 10—1

Method: ADAPT_ORDRE2

Node \({x}_{2}\), move (\(m\))

4.9867 10—1

Note: the C modeling tests are duplicated because we want to test the modal calculation on the projected matrices with automatic passage to the MUMPS solver while the user requested the MULT_FRONT solver, which is not available in this case. The results are the same.