[SMApp] - RBE2

[DrexlerTUM]

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name: RBE2 Process & Test
about: creates a RBE2 (kinematic) coupling between a master and slave nodes within the StructuralMechanicsApplication

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📝 Description

RBE2_process.py:
The process generates a RBE2-coupling with a master and a set of slave nodes. The RBE2 elements are defined in Nastran. A RBE2 coupling represents a kinematic coupling (rigid) between a master and the slave nodes. The coupling is assumed to be infinitely stiff and the slave nodes are exactly following the movement of the master. The displacement $u_S$ and rotation $\theta_S$ of the slave nodes depending on the displacement $u_M$ and rotation $\theta_M$ of the master node is described by:

• $u_S = u_M + \theta_M \times r$
• $\theta_S = \theta_M$

Hereby $r=x_S -x_M$ describes the relative position of the slave node with respect to the master node
The coupling is implemented using the Kratos LinearMasterSlaveConstraint class.

Key changes

implementation of RBE2 for FE-applications

Validation

test_RBE2.py:
The test verifies the RBE2 connection between a master node and multiple slave nodes.
Therefore a simple panel model is created in Kratos, which is fixed on one side. On the other side the nodes of the panel are connected to a master node via the RBE2-coupling. A prescribed displacement ($u_x, u_y, u_z$) or rotation ($\theta_x, \theta_y, \theta_z$) is applied to the master node, and the resulting displacements and rotations of the slave nodes are compared against reference results obtained from Nastran.
The test verifies similar results with a relative tolerance between Nastran and Kratos within the range 0.00001.

🆕 Changelog

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