Lagrange Multipliers (MPC-based)

MPC-based contact utilizes multi-point constraints (MPCs) to define a tied contact between the main and secondary surfaces.

It is activated using CONTPRM,TIE,MPC and TIE Bulk Data Entries. All TIE contacts in the model are defined using the MPC-based method. This method uses Lagrange Multipliers and is not applicable to CONTACT Bulk Data Entries of TYPE=FREEZE.
Figure 1.


Attention:
  1. Results of an MPC-based TIE contact analysis may not be accurate if there is a physical gap between the main and secondary surfaces. The six rigid body modes may not be proper in such cases.
  2. MPC-based TIE contact is currently not supported with MODCHG.
  3. MPC-based TIE contact is currently supported for Linear Static, Linear Transient, Nonlinear Static, and Nonlinear Transient Analysis. It is supported for both Small and Large Displacement Nonlinear Analysis.