2023-05-30T08:29:07.000-0400

Simcenter Nastran
Simcenter 3D

Using RBE3 elements with many legs and a mass element on the intepolated node can bring to a dense mass matrix and slow calculation time. In this article we will see how to improve calculation time.

Attachments: | DenseMassMatrix2206.7z (998 KB) |

In the attached example, which was developed in version 2206, we have a cube made of shell element at which center there is a conentrated mass; this mass is connected to all other nodes by means of an RBE3. A normal mode solution sol103 is taken. When the solution is launched, the following warning is thrown:

If we change the Rigid element Method, by setting RIGID=LAGRAN in deck case control or Rigid Element Method as Lagrange multiplier in solution case control tab in Simcenter 3D interface (as depicted in the following figure), the previous warnig disappear and calculation time significantly decreases (from more then 4 minutes to 8 seconds in the attached example).