3. Modeling A#

3.1. Characteristics of modeling#

Discreet element in type translation DIS_T

_images/10000262000010F30000048C5BF6BDB2083723BD.svg

Characteristics of the elements:

At nodes \(\mathrm{P1}\) and \(\mathrm{P2}\): mass matrices of type M_T_D_N with \(m=100\mathrm{kg}\).

Between \(\mathrm{P1}\) and \(\mathrm{P2}\): a K_T_D_L stiffness matrix with \({K}_{x}={10}^{6}N/m\)

Boundary conditions:

All degrees of freedom are locked except degree of freedom \(\mathrm{DX}\) from node \(\mathrm{P2}\).

3.2. Characteristics of the mesh#

Number of knots: 2

Number of meshes and types: 1 SEG2, 2 POI1

3.3. Features tested#

We test the linear transient calculation functionalities on a physical basis and on a modal basis of the operator DYNA_VIBRA.

3.4. Tested sizes and results#

Dynamic response

The position of the mass is tested after a period of time, i.e. 2 seconds. In addition, the value of mode 1 modal participation is tested. Since it is a unique mode and is standardized according to the node that carries the mass, modal participation is identical to displacement.

Identification

Reference

Tolerance

DYNA_VIBRA /physical base (NEWMARK)

\(1\text{m}\)

1.E-4%

DYNA_VIBRA /physical base (DIFF_CENTRE)

\(1\text{m}\)

1.E-4%

DYNA_VIBRA /modal_base (EULER)

\(1\text{m}\)

0.01%

DYNA_VIBRA (modal participation)

\(1\text{m}\)

0.01%

We also test the value of the speed (in m/s) of the mass at t = 1.5 s

i.e. when it passes through the static equilibrium position \((x=0)\).

DYNA_VIBRA /physical base (NEWMARK)

\(\pi\)

1.E-4%

DYNA_VIBRA /modal_base (EULER)

\(\pi\)

0.1%