def main():
import os
import numpy as nm
import matplotlib.pyplot as plt
from sfepy.fem import MeshIO
import sfepy.linalg as la
from sfepy.mechanics.contact_planes import (ContactPlane, plot_polygon,
plot_points)
conf_dir = os.path.dirname(__file__)
io = MeshIO.any_from_filename(filename_mesh, prefix_dir=conf_dir)
bb = io.read_bounding_box()
outline = [vv for vv in la.combine(zip(*bb))]
ax = plot_points(None, nm.array(outline), 'r*')
for name in ['cp%d' % ii for ii in range(4)]:
cpc = materials[name][0]
cp = ContactPlane(cpc['.a'], cpc['.n'], cpc['.bs'])
v1, v2 = la.get_perpendiculars(cp.normal)
ax = plot_polygon(ax, cp.bounds)
ax = plot_polygon(
ax, nm.r_[cp.anchor[None, :],
cp.anchor[None, :] + cp.normal[None, :]])
ax = plot_polygon(ax, nm.r_[cp.anchor[None, :],
cp.anchor[None, :] + v1])
ax = plot_polygon(ax, nm.r_[cp.anchor[None, :],
cp.anchor[None, :] + v2])
plt.show()
def get_fargs(self,
force_pars,
normal,
anchor,
bounds,
virtual,
state,
mode=None,
term_mode=None,
diff_var=None,
**kwargs):
sg, _ = self.get_mapping(virtual)
assert_((force_pars >= 0.0).all(),
'force parameters must be non-negative!')
if self.cp is None:
self.cp = ContactPlane(anchor, normal, bounds)
ig = self.char_fun.ig
qps = self.get_physical_qps()
qp_coors = qps.values[ig]
u_qp = self.get(state, 'val').reshape(qp_coors.shape)
# Deformed QP coordinates.
coors = u_qp + qp_coors
force = nm.zeros(coors.shape[0], dtype=nm.float64)
# Active points in contact change with displacements!
ii = self.cp.mask_points(coors)
k = force_pars[..., 0]
f0 = force_pars[..., 1]
k.shape = f0.shape = force.shape
ir = f0 >= 1e-14
eps = nm.where(ir, -2.0 * f0 / k, 0.0)
a = nm.zeros_like(eps)
a[ir] = k[ir]**2 / (4.0 * f0[ir])
if diff_var is None:
if ii.any():
d = self.cp.get_distance(coors[ii])
# Force in the plane normal direction.
force[ii] = self.smooth_f(d, k[ii], f0[ii], a[ii], eps[ii], 0)
fmode = 0
else:
if ii.any():
d = self.cp.get_distance(coors[ii])
# Force in the plane normal direction derivative.
force[ii] = self.smooth_f(d, k[ii], f0[ii], a[ii], eps[ii], 1)
fmode = 1
force.shape = qps.shape[ig][:2] + (1, 1)
return force, self.cp.normal, sg, fmode
