Rigid Links in NASTRAN
When you run a FEM analysis,
Creo Simulate writes RBAR or RBE2 cards to the
output.nas file depending on the value of the configuration option
fem_output_rigid_link_as_rbar and the type of rigid link created.
If the configuration option is set to no and the rigid link has more than one node on the dependent side RBE2 cards are written to the.nas file. If the configuration option is set to yes or the rigid element has a single node on the dependent side then RBAR cards are written to the .nas file.
When the configuration option fem_output_rigid_link_as_rbar is set to its default value of no, Creo Simulate writes the following types of advanced rigid links as single RBE2 cards in the .nas file:
• A single point on the independent side and multiple points on the dependent side.
• A single point on the independent side and edges or curves on the dependent side.
• A single point on the independent side and a surface or multiple surfaces on the dependent side.
• A pattern of points or point intent feature on the independent side and multiple points on the dependent side.
• All simple rigid links with references as points, edges, curves and surfaces, where the rigid link is created with more than one node on the dependent side.
In the case of the following types of advanced rigid links, Creo Simulate writes RBAR cards irrespective of the value of the configuration option fem_output_rigid_link_as_rbar:
• A point feature or pattern of points on the independent side and edges, curves or surfaces on the dependent side.
• A surface on the independent side and a surface on the dependent side.
• A point feature or pattern of points on both the independent and dependent sides.
• For all mesh files with advanced rigid link elements created prior to Creo 1.
For the following types of simple rigid links Creo Simulate writes RBAR cards in the .nas file irrespective of the value of the configuration option fem_output_rigid_link_as_rbar:
• When the dependent side has only one node
• For all mesh files with simple rigid link elements created prior to Creo 1.