4.1.1.8.1.1. pyfem.solvers.BuckEigSolver module

class BuckEigSolver(props: Properties, globdat: GlobalData)

Bases: BaseModule

Eigenvalue solver for buckling analysis.

This solver assembles the initial and current tangent stiffness matrices, solves the static problem to obtain the prebuckling state and computes eigenvalues/eigenvectors for the buckling problem.

tol

convergence tolerance for internal iterations

iterMax

maximum iterations (unused currently)

fext

external force vector (numpy array-like)

run(props: Properties, globdat: GlobalData) → None

Execute the buckling eigenvalue analysis.

Steps: - assemble initial tangent stiffness K0 and internal force fint - assemble external force fext and solve for prebuckling state - assemble updated stiffness K and compute eigenpairs using DOF solver - commit element history and deactivate model if appropriate

Parameters:

• props – analysis properties

• globdat – global data structure (modified in-place)

printResults(eigenvals: Sequence[float]) → None

Print computed eigenvalues.

Parameters:

eigenvals – iterable of eigenvalues (loads) to report