2020-06-29T17:18:54.000-0400

Simcenter Nastran
Simcenter 3D

There are two ways to create MPC equations in Simcenter 3D:

**1D Connection **or **Element Create **dialog box, select the **Constraint Equations **option from the **Type **list to create the element between the nodes you select.

Next, you can define the coefficients for the selected independent degrees-of-freedom in**Associated Data** or **Manage Element Associated Data** (both listed under group **Elements**)

If you want to constrain all six DOFs for the dependent node, you must create six MPC Elements and the associated**Constraint Equations**.

For example, 3 constraint equations are defined in the table for the 3 MPC elements. The first row for each equation (e.g. rows 2, 9, 16) in the table is the dependent nodes (e.g. 19039, 19045, 19046). You cannot specify coefficients for the degrees-of-freedom for the dependent node.

User can select the**Solver Syntax Preview** for any MPC element to see the associated constraint equation (which should be the same as what displayed in the **Manage Element Associated Data)**

After you defined the MPC elements in the FEM file, you can apply constraints to these elements in the Simulation file. Use the**Multi MPC **option in the **Manual Coupling **dialog box to constrain selected MPC elements. Without this step, the MPC equations will not be exported.

**MPC **option in the **Manual Coupling **dialog box to define the Dependent/Independent nodes and the associated DOFs and coefficients. Toggle on the **Unique DOF Values** to define different coefficients for different DOFs.

Again, if you want to constrain all six DOFs for the dependent node, you must create six MPC equations.

- Create MPC (constraint) elements

Next, you can define the coefficients for the selected independent degrees-of-freedom in

If you want to constrain all six DOFs for the dependent node, you must create six MPC Elements and the associated

For example, 3 constraint equations are defined in the table for the 3 MPC elements. The first row for each equation (e.g. rows 2, 9, 16) in the table is the dependent nodes (e.g. 19039, 19045, 19046). You cannot specify coefficients for the degrees-of-freedom for the dependent node.

User can select the

After you defined the MPC elements in the FEM file, you can apply constraints to these elements in the Simulation file. Use the

- Define MPC (constraint) equations directly

Again, if you want to constrain all six DOFs for the dependent node, you must create six MPC equations.