Fix Constraint

The fix constraint is the most basic type of single-point constraint in Femora. It applies constraints to specific degrees of freedom at individual nodes.

Description

The fix constraint works by directly specifying which degrees of freedom should be constrained at a particular node. Each degree of freedom can be set as either free (0) or fixed (1).

Parameters

  • node_tag (int): The tag (ID) of the node to be constrained

  • dofs (List[int]): List of DOF constraint values (0 or 1) * 0 = unconstrained (free) * 1 = constrained (fixed)

Usage

import femora as fm

# Create Femora instance


# First assemble the mesh
fm.assembler.Assemble(merge_points=True)

# Apply fix constraint to node 10
# Fix translations (DOFs 1,2,3) but allow rotations (DOFs 4,5,6)
fm.constraint.sp.fix(node_tag=10, dofs=[1, 1, 1, 0, 0, 0])

# Fix all degrees of freedom at node 20
fm.constraint.sp.fix(node_tag=20, dofs=[1, 1, 1, 1, 1, 1])

# Fix only X direction at node 30
fm.constraint.sp.fix(node_tag=30, dofs=[1, 0, 0, 0, 0, 0])