SfePy NTC

Source code for sfepy.terms.terms_hyperelastic_base

import numpy as nm
from sfepy.terms.terms import Term, terms

_msg_missing_data = 'missing family data!'

[docs]class HyperElasticBase(Term): """ Base class for all hyperelastic terms in TL/UL formulation. `HyperElasticBase.__call__()` computes element contributions given either stress (-> rezidual) or tangent modulus (-> tangent sitffnes matrix), i.e. constitutive relation type (CRT) related data. The CRT data are computed in subclasses implementing particular CRT (e.g. neo-Hookean material), in self.compute_crt_data(). Modes: - 0: total formulation - 1: updated formulation Notes ----- This is not a proper Term! """ arg_types = ('material', 'virtual', 'state') arg_shapes = {'material' : '1, 1', 'virtual' : ('D', 'state'), 'state' : 'D'} @staticmethod
[docs] def integrate(out, val_qp, vg, fmode): if fmode == 2: out[:] = val_qp status = 0 else: status = vg.integrate(out, val_qp, fmode) return status
@staticmethod
[docs] def function(out, fun, *args): return fun(out, *args)
def __init__(self, *args, **kwargs): Term.__init__(self, *args, **kwargs) self.stress_cache = None
[docs] def get_family_data(self, state, cache_name, data_names): """ Notes ----- `data_names` argument is ignored for now. """ name = state.name step_cache = state.evaluate_cache.setdefault(cache_name, {}) cache = step_cache.setdefault(self.arg_steps[name], {}) vg, _, key = self.get_mapping(state, return_key=True) data_key = key + (self.arg_derivatives[name],) if data_key in cache: out = cache[data_key] else: out = self.compute_family_data(state) cache[data_key] = out return out
[docs] def compute_stress(self, mat, family_data, **kwargs): out = nm.empty_like(family_data.green_strain) get = family_data.get fargs = [get(name, msg_if_none=_msg_missing_data) for name in self.family_data_names] self.stress_function(out, mat, *fargs, **kwargs) return out
[docs] def compute_tan_mod(self, mat, family_data, **kwargs): shape = list(family_data.green_strain.shape) shape[-1] = shape[-2] out = nm.empty(shape, dtype=nm.float64) get = family_data.get fargs = [get(name, msg_if_none=_msg_missing_data) for name in self.family_data_names] self.tan_mod_function(out, mat, *fargs, **kwargs) return out
[docs] def get_fargs(self, mat, virtual, state, mode=None, term_mode=None, diff_var=None, **kwargs): vg, _ = self.get_mapping(state) fd = self.get_family_data(state, self.fd_cache_name, self.family_data_names) if mode == 'weak': if diff_var is None: stress = self.compute_stress(mat, fd, **kwargs) self.stress_cache = stress tan_mod = nm.array([0], ndmin=4, dtype=nm.float64) fmode = 0 else: stress = self.stress_cache if stress is None: stress = self.compute_stress(mat, fd, **kwargs) tan_mod = self.compute_tan_mod(mat, fd, **kwargs) fmode = 1 return (self.weak_function, stress, tan_mod, fd.mtx_f, fd.det_f, vg, fmode, self.hyperelastic_mode) elif mode in ('el_avg', 'qp'): if term_mode == 'strain': out_qp = fd.green_strain elif term_mode == 'stress': out_qp = self.compute_stress(mat, fd, **kwargs) else: raise ValueError('unsupported term mode in %s! (%s)' % (self.name, term_mode)) fmode = {'el_avg' : 1, 'qp' : 2}[mode] return self.integrate, out_qp, vg, fmode else: raise ValueError('unsupported evaluation mode in %s! (%s)' % (self.name, mode))
[docs] def get_eval_shape(self, mat, virtual, state, mode=None, term_mode=None, diff_var=None, **kwargs): n_el, n_qp, dim, n_en, n_c = self.get_data_shape(state) sym = dim * (dim + 1) / 2 if mode != 'qp': n_qp = 1 return (n_el, n_qp, sym, 1), state.dtype
[docs]class DeformationGradientTerm(Term): r""" Deformation gradient :math:`\ull{F}` in quadrature points for `term_mode='def_grad'` (default) or the jacobian :math:`J` if `term_mode='jacobian'`. Supports 'eval', 'el_avg' and 'qp' evaluation modes. :Definition: .. math:: \ull{F} = \pdiff{\ul{x}}{\ul{X}}|_{qp} = \ull{I} + \pdiff{\ul{u}}{\ul{X}}|_{qp} \;, \\ \ul{x} = \ul{X} + \ul{u} \;, J = \det{(\ull{F})} :Arguments: - parameter : :math:`\ul{u}` """ name = 'ev_def_grad' arg_types = ('parameter',) arg_shapes = {'parameter' : 'D'} @staticmethod
[docs] def function(out, vec, vg, econn, term_mode, fmode): d = 1 if term_mode == 'jacobian' else vg.dim out_qp = nm.empty((out.shape[0], vg.n_qp, d, d), dtype=out.dtype) mode = 1 if term_mode == 'jacobian' else 0 terms.dq_def_grad(out_qp, vec, vg, econn, mode) if fmode == 2: out[:] = out_qp status = 0 else: status = vg.integrate(out, out_qp, fmode) return status
[docs] def get_fargs(self, parameter, mode=None, term_mode=None, diff_var=None, **kwargs): ap, vg = self.get_approximation(parameter) vec = self.get_vector(parameter) fmode = {'eval' : 0, 'el_avg' : 1, 'qp' : 2}.get(mode, 1) return vec, vg, ap.econn, term_mode, fmode
[docs] def get_eval_shape(self, parameter, mode=None, term_mode=None, diff_var=None, **kwargs): n_el, n_qp, dim, n_en, n_c = self.get_data_shape(parameter) if mode != 'qp': n_qp = 1 if term_mode == 'jacobian': return (n_el, n_qp, 1, 1), parameter.dtype else: # 'def_grad' return (n_el, n_qp, dim, dim), parameter.dtype