fedoo.problem.NonLinearNewmark

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

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.

Parameters:

  • assembly (Assembly-like object or str) – Assembly used by the nonlinear problem, or its registered name.

  • beta (float, default=0.25) – Newmark acceleration parameter.

  • gamma (float, default=0.5) – Newmark velocity parameter.

  • nlgeom (bool or str, default=False) – Geometric-nonlinearity option forwarded to NonLinear.

  • first_order_integrator (fedoo.time.BackwardEuler, optional) – Integrator for first-order evolution terms. A default Backward-Euler integrator is created when omitted.

  • name (str, default="MainProblem") – Name of the problem.

  • 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)