1. Principle of the test

The model (made up of 3D meshes, or shell meshes or girder meshes) is subject to an imposed displacement on part of its edge (there is no « force » loading).

As the imposed displacement corresponds to a simple rotation of the edge, the complete solution is also the imposed rotation.

The structure does not deform, its stress state is zero.

The models tested are those that accept large rotations:

3D, COQUE_3D, POU_D_T_GD, POU_D_EM, and POU_D_TGM

For the three structure models (which have rotation ddls), it is

interesting to see how the big rotations are « made up ». Indeed, the big

rotations are not additive quantities. For this, the imposed displacement is

broken down into 4 steps:

• a rotation of angle phi0 around Oz between the moments 0. and 1.

• a rotation of angle phi0 around Oy between the moments 1. and 2.

• a rotation of angle phi0 around Ox between the moments 2. and 3.

• the rotation allowing to return to the initial position.

1.1. Benchmark results, validation

The solution while on the move is known: it is imposed rotation. The solution under stress is known: a zero stress state.

For the movement, we check that the U - Uref field has a maximum and a minimum close to zero.