FixX Constraint

The fixX constraint is a coordinate-based constraint that applies constraints to all nodes located at a specific X-coordinate.

Description

Unlike the basic fix constraint which targets specific nodes by tag, the fixX constraint targets nodes based on their X-coordinate position. This is particularly useful for applying boundary conditions to an entire face or plane of nodes without needing to specify each node individually.

Parameters

  • xCoordinate (float): The x-coordinate of nodes to be constrained

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

  • tol (float, optional): Tolerance for coordinate comparison (default: 1e-10)

Usage

import femora as fm

# Create Femora instance


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

# Fix all nodes at X=0 (e.g., left face of a model)
# Fix translations (DOFs 1,2,3) but allow rotations (DOFs 4,5,6)
fm.constraint.sp.fixX(xCoordinate=0.0, dofs=[1, 1, 1, 0, 0, 0])

# Fix all nodes at X=10 (e.g., right face of model)
# Use a larger tolerance for floating-point comparison
fm.constraint.sp.fixX(xCoordinate=10.0, dofs=[1, 0, 0, 0, 0, 0], tol=1e-6)