Learning Forum

[mmia1]

Hi

I remember using Multiple point constraints (MPC) in ABAQUS where all the slave nodes are connected to one master node and the displacement applied at that master node was followed by slave nodes. 

Is there any way I can do this exact same thing in LSDyna. Please see the attached image. I want to connect all the circumferential nodes to the center master node. And then I want to apply Z displacement at that center master node and I want all the slave nodes (circumferential nodes) to follow that. Thanks.

 

[Jim Day]

I don't know Abaqus, but I get the impression there are different forms of MPCs. If you want all the nodes to behave as a rigid body, the LS-DYNA keyword is *CONSTRAINED_NODAL_RIGID_BODY (like an RBE2 in Nastran). If you want to retain deformability in the circumference of the pipe, then consider *CONSTRAINED_INTERPOLATION (like an RBE3 in Nastran). The latter would be appropriate in the case where you wanted to distribute load from the center node to the nodes on the circumference.