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*MPC

Keyword type: model definition

With this keyword card a multiple point constraint is defined, usually a nonlinear one. Right now, three different MPC's can be selected.

- A plane MPC (name PLANE). This MPC specifies that all nodes listed within this MPC card should stay in a plane. The first three nodes are the defining nodes and should not lie on a line. For all subsequent nodes a nonlinear MPC is generated expressing that they stay within the plane. Notice that the plane can move during deformation, depending on the motion of the defining nodes.

- A straight line MPC (name STRAIGHT). This MPC expresses that all nodes listed within this MPC card should stay on a straight line. The first two nodes are the defining nodes and should not coincide. For all subsequent nodes two nonlinear MPC's are generated expressing that they stay on the straight line. Notice that the straight line can move during deformation, depending on the motion of its defining nodes.

- A user MPC (name to be defined by the user). With this option the user can define new nonlinear MPC's.

If NLGEOM is not specified on the *STEP card, the MPC is linearized. Note that depending on the degree of nonlinearity of the MPC linearization can lead to significant errors in the results. It is generally advisable to start with a linear calculation to check the correctness of the structure, loading and boundary conditions. If the linear calculation runs satisfactorily, a geometrically nonlinear calculation should be performed.

There are no parameters for this keyword card.

First line:

- *MPC

Second line:

- MPC type
- list of nodes participating in the MPC: maximum 15 entries. Zero entries are discarded.

Following lines (as many as needed):

- list of nodes participating in the MPC: maximum 16 entries. Zero entries are discarded.

    Example:

    *MPC
    PLANE,3,8,15,39,14

specifies that nodes 3, 8, 15, 39 and 14 should stay in a plane. The plane is defined by nodes 3, 8 and 15. They should not be colinear.

Example files: beammr, beamplane, beamstraight.

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