fedoo.problem.NonLinearNewmark

class NonLinearNewmark(assembly, beta=0.25, gamma=0.5, nlgeom=False, name='MainProblem', first_order_integrator=None)

Create a nonlinear Newmark problem with default time integrators.

This is a convenience factory around NonLinear. It attaches a Newmark integrator for second-order evolutions and a Backward-Euler integrator for first-order evolutions.

Note

The signature changed: the mass is now derived from the material density (material.set_density(rho)) or weakform.set_inertia(...), so a separate mass assembly is no longer passed. The legacy NonLinearNewmark(stiffness, mass, beta, gamma) form is rejected with an explicit error.

__init__(**kwargs)