Supports

Supports constrain node DOFs, defining the boundary conditions of the structure.

Set and clear supports

model.SetSupport(baseNode, DoF.Fixed);
model.SetSupport(rollerNode, DoF.RollerZ);

model.ClearSupport(rollerNode);

Available DoF presets

Preset	Restrained translations	Restrained rotations	Typical use
DoF.Fixed	X, Y, Z	Rx, Ry, Rz	Rigid base connection
DoF.Pinned	X, Y, Z	None	Simple support, allows rotation
DoF.RollerX	Y, Z	None	Free to slide in X
DoF.RollerY	X, Z	None	Free to slide in Y
DoF.RollerZ	X, Y	None	Free to slide in Z (vertical roller)

Support object

A Support stores:

• Node — the node being constrained
• DegreeOfFreedom (DoF) — which DOFs are restrained

Manage supports through StructuralModel.SetSupport(...) and ClearSupport(...) to keep model collections synchronised.

Notes

• A model must have sufficient supports to prevent rigid body motion. If the global stiffness matrix is singular (mechanism), the solver will throw an exception.
• Setting a support on a node that already has one replaces it.
• Clearing a support removes all restraints at that node.
• Support changes invalidate cached results.