def test_calc_linear_buckling():
E11 = 71.e9
nu = 0.33
plyt = 0.007
lam = read_stack([0], plyt=plyt, laminaprop=(E11, E11, nu))
ans = {
'edge-based': 41.85273,
'cell-based': 6.98852939,
'cell-based-no-smoothing': 4.921956
}
for prop_from_nodes in [True, False]:
for k0s_method in [
'edge-based', 'cell-based', 'cell-based-no-smoothing'
]:
mesh = read_mesh(
os.path.join(THISDIR, 'nastran_plate_16_nodes.dat'))
for tria in mesh.elements.values():
tria.prop = lam
for node in mesh.nodes.values():
node.prop = lam
k0 = calc_k0(mesh, prop_from_nodes)
add_k0s(k0, mesh, prop_from_nodes, k0s_method, alpha=0.2)
# running static subcase first
dof = 5
n = k0.shape[0] // 5
fext = np.zeros(n * dof, dtype=np.float64)
fext[mesh.nodes[4].index * dof + 0] = -500.
fext[mesh.nodes[7].index * dof + 0] = -500.
fext[mesh.nodes[5].index * dof + 0] = -1000.
fext[mesh.nodes[6].index * dof + 0] = -1000.
# boundary conditions
def bc(K):
for i in [1, 10, 11, 12]:
for j in [0, 1, 2]:
K[mesh.nodes[i].index * dof + j, :] = 0
K[:, mesh.nodes[i].index * dof + j] = 0
for i in [2, 3, 4, 5, 6, 7, 8, 9]:
for j in [1, 2]:
K[mesh.nodes[i].index * dof + j, :] = 0
K[:, mesh.nodes[i].index * dof + j] = 0
bc(k0)
k0 = coo_matrix(k0)
d = solve(k0, fext, silent=True)
kG = calc_kG(d, mesh, prop_from_nodes)
bc(kG)
kG = coo_matrix(kG)
eigvals, eigvecs = lb(k0, kG, silent=True)
print('k0s_method, eigvals[0]', k0s_method, eigvals[0])
assert np.isclose(eigvals[0], ans[k0s_method])
def test_calc_linear_static():
mesh = read_mesh(os.path.join(THISDIR, 'nastran_plate_16_nodes.dat'))
E11 = 71.e9
nu = 0.33
plyt = 0.007
lam = read_stack([0], plyt=plyt, laminaprop=(E11, E11, nu))
for tria in mesh.elements.values():
tria.prop = lam
for node in mesh.nodes.values():
node.prop = lam
for prop_from_nodes in [False, True]:
for k0s_method in ['cell-based', 'cell-based-no-smoothing']: #, 'edge-based'
k0 = calc_k0(mesh, prop_from_nodes)
add_k0s(k0, mesh, prop_from_nodes, k0s_method, alpha=0.2)
k0run = k0.copy()
dof = 5
n = k0.shape[0] // dof
fext = np.zeros(n*dof, dtype=np.float64)
fext[mesh.nodes[4].index*dof + 2] = 500.
fext[mesh.nodes[7].index*dof + 2] = 500.
fext[mesh.nodes[5].index*dof + 2] = 1000.
fext[mesh.nodes[6].index*dof + 2] = 1000.
i, j = np.indices(k0run.shape)
# boundary conditions
for nid in [1, 10, 11, 12]:
for j in [0, 1, 2, 3]:
k0run[mesh.nodes[nid].index*dof+j, :] = 0
k0run[:, mesh.nodes[nid].index*dof+j] = 0
k0run = coo_matrix(k0run)
u = solve(k0run, fext, silent=True)
ans = np.loadtxt(os.path.join(THISDIR, 'nastran_plate_16_nodes.result.txt'),
dtype=float)
xyz = np.array([n.xyz for n in mesh.nodes.values()])
ind = np.lexsort((xyz[:, 1], xyz[:, 0]))
xyz = xyz[ind]
nodes = np.array(list(mesh.nodes.values()))[ind]
pick = [n.index for n in nodes]
assert np.allclose(u[2::5][pick].reshape(4, 4).T, ans, rtol=0.05)
from meshless.espim.read_mesh import read_mesh
from meshless.espim.plate2d_calc_k0 import calc_k0
from meshless.espim.plate2d_calc_kG import calc_kG
from meshless.espim.plate2d_add_k0s import add_k0s
THISDIR = os.path.dirname(inspect.getfile(inspect.currentframe()))
E11 = 71.e9
nu = 0.33
plyt = 0.007
laminaprop = (E11, E11, nu)
lam = read_stack([0], plyt=plyt, laminaprop=laminaprop, calc_scf=True)
prop_from_nodes = False
k0s_method = 'cell-based'
mesh = read_mesh(os.path.join(THISDIR, 'nastran_test.dat'))
nodes = mesh.nodes.values()
for tria in mesh.elements.values():
tria.prop = lam
for node in nodes:
node.prop = lam
k0 = calc_k0(mesh, prop_from_nodes)
add_k0s(k0, mesh, prop_from_nodes, k0s_method)
dof = 5
N = k0.shape[0] // 5
# boundary conditions
def bc(K):
ids = [n.nid for n in nodes if np.isclose(n.xyz[0], 0.)]
def test_read_mesh():
mesh = read_mesh(os.path.join(THISDIR, 'nastran_plate_16_nodes.dat'))
assert len(mesh.nodes) == 16
assert len(mesh.elements) == 18
assert len(mesh.edges) == 33