mechanics done

This commit is contained in:
Samad Vakili 2020-06-09 21:27:08 +02:00
parent d365cc9e12
commit 694b7ec3c5
1 changed files with 29 additions and 45 deletions

View File

@ -8,16 +8,12 @@ def Cauchy(P,F):
Parameters
----------
F : numpy.ndarray of shape (:,3,3) or (3,3)
F : numpy.ndarray of shape (...,3,3)
Deformation gradient.
P : numpy.ndarray of shape (:,3,3) or (3,3)
P : numpy.ndarray of shape (...,3,3)
First Piola-Kirchhoff stress.
"""
if _np.shape(F) == _np.shape(P) == (3,3):
sigma = 1.0/_np.linalg.det(F) * _np.dot(P,F.T)
else:
#sigma = _np.einsum('i,ijk,ilk->ijl',1.0/_np.linalg.det(F),P,F)
sigma = _np.einsum('...,...ij,...kj->...ik',1.0/_np.linalg.det(F),P,F)
return symmetric(sigma)
@ -44,7 +40,7 @@ def eigenvalues(T_sym):
Parameters
----------
T_sym : numpy.ndarray of shape (:,3,3) or (3,3)
T_sym : numpy.ndarray of shape (...,3,3)
Symmetric tensor of which the eigenvalues are computed.
"""
@ -59,7 +55,7 @@ def eigenvectors(T_sym,RHS=False):
Parameters
----------
T_sym : numpy.ndarray of shape (:,3,3) or (3,3)
T_sym : numpy.ndarray of shape (...,3,3)
Symmetric tensor of which the eigenvectors are computed.
RHS: bool, optional
Enforce right-handed coordinate system. Default is False.
@ -68,9 +64,6 @@ def eigenvectors(T_sym,RHS=False):
(u,v) = _np.linalg.eigh(symmetric(T_sym))
if RHS:
if _np.shape(T_sym) == (3,3):
if _np.linalg.det(v) < 0.0: v[:,2] *= -1.0
else:
v[_np.linalg.det(v) < 0.0,:,2] *= -1.0
return v
@ -81,7 +74,7 @@ def left_stretch(T):
Parameters
----------
T : numpy.ndarray of shape (:,3,3) or (3,3)
T : numpy.ndarray of shape (...,3,3)
Tensor of which the left stretch is computed.
"""
@ -94,13 +87,12 @@ def maximum_shear(T_sym):
Parameters
----------
T_sym : numpy.ndarray of shape (:,3,3) or (3,3)
T_sym : numpy.ndarray of shape (...,3,3)
Symmetric tensor of which the maximum shear is computed.
"""
w = eigenvalues(T_sym)
return (w[0] - w[2])*0.5 if _np.shape(T_sym) == (3,3) else \
(w[...,0] - w[...,2])*0.5
return (w[...,0] - w[...,2])*0.5
def Mises_strain(epsilon):
@ -109,7 +101,7 @@ def Mises_strain(epsilon):
Parameters
----------
epsilon : numpy.ndarray of shape (:,3,3) or (3,3)
epsilon : numpy.ndarray of shape (...,3,3)
Symmetric strain tensor of which the von Mises equivalent is computed.
"""
@ -122,7 +114,7 @@ def Mises_stress(sigma):
Parameters
----------
sigma : numpy.ndarray of shape (:,3,3) or (3,3)
sigma : numpy.ndarray of shape (...,3,3)
Symmetric stress tensor of which the von Mises equivalent is computed.
"""
@ -135,15 +127,12 @@ def PK2(P,F):
Parameters
----------
P : numpy.ndarray of shape (...,3,3) or (3,3)
P : numpy.ndarray of shape (...,3,3)
First Piola-Kirchhoff stress.
F : numpy.ndarray of shape (...,3,3) or (3,3)
F : numpy.ndarray of shape (...,3,3)
Deformation gradient.
"""
if _np.shape(F) == _np.shape(P) == (3,3):
S = _np.dot(_np.linalg.inv(F),P)
else:
S = _np.einsum('...jk,...kl->...jl',_np.linalg.inv(F),P)
return symmetric(S)
@ -154,7 +143,7 @@ def right_stretch(T):
Parameters
----------
T : numpy.ndarray of shape (:,3,3) or (3,3)
T : numpy.ndarray of shape (...,3,3)
Tensor of which the right stretch is computed.
"""
@ -167,7 +156,7 @@ def rotational_part(T):
Parameters
----------
T : numpy.ndarray of shape (:,3,3) or (3,3)
T : numpy.ndarray of shape (...,3,3)
Tensor of which the rotational part is computed.
"""
@ -199,7 +188,7 @@ def strain_tensor(F,t,m):
Parameters
----------
F : numpy.ndarray of shape (:,3,3) or (3,3)
F : numpy.ndarray of shape (...,3,3)
Deformation gradient.
t : {V, U}
Type of the polar decomposition, V for left stretch tensor and U for right stretch tensor.
@ -207,12 +196,11 @@ def strain_tensor(F,t,m):
Order of the strain.
"""
F_ = F.reshape(1,3,3) if F.shape == (3,3) else F
if t == 'V':
B = _np.matmul(F_,transpose(F_))
B = _np.matmul(F,transpose(F))
w,n = _np.linalg.eigh(B)
elif t == 'U':
C = _np.matmul(transpose(F_),F_)
C = _np.matmul(transpose(F),F)
w,n = _np.linalg.eigh(C)
if m > 0.0:
@ -225,8 +213,7 @@ def strain_tensor(F,t,m):
else:
eps = _np.matmul(n,_np.einsum('...j,...kj->...jk',0.5*_np.log(w),n))
return eps.reshape(3,3) if _np.shape(F) == (3,3) else \
eps
return eps
def symmetric(T):
@ -235,7 +222,7 @@ def symmetric(T):
Parameters
----------
T : numpy.ndarray of shape (...,3,3) or (3,3)
T : numpy.ndarray of shape (...,3,3)
Tensor of which the symmetrized values are computed.
"""
@ -248,12 +235,11 @@ def transpose(T):
Parameters
----------
T : numpy.ndarray of shape (...,3,3) or (3,3)
T : numpy.ndarray of shape (...,3,3)
Tensor of which the transpose is computed.
"""
return T.T if _np.shape(T) == (3,3) else \
_np.swapaxes(T,axis2=-2,axis1=-1)
return _np.swapaxes(T,axis2=-2,axis1=-1)
def _polar_decomposition(T,requested):
@ -262,7 +248,7 @@ def _polar_decomposition(T,requested):
Parameters
----------
T : numpy.ndarray of shape (:,3,3) or (3,3)
T : numpy.ndarray of shape (...,3,3)
Tensor of which the singular values are computed.
requested : iterable of str
Requested outputs: R for the rotation tensor,
@ -270,16 +256,15 @@ def _polar_decomposition(T,requested):
"""
u, s, vh = _np.linalg.svd(T)
R = _np.dot(u,vh) if _np.shape(T) == (3,3) else \
_np.einsum('...ij,...jk->...ik',u,vh)
R = _np.einsum('...ij,...jk->...ik',u,vh)
output = []
if 'R' in requested:
output.append(R)
if 'V' in requested:
output.append(_np.dot(T,R.T) if _np.shape(T) == (3,3) else _np.einsum('...ij,...kj->...ik',T,R))
output.append(_np.einsum('...ij,...kj->...ik',T,R))
if 'U' in requested:
output.append(_np.dot(R.T,T) if _np.shape(T) == (3,3) else _np.einsum('...ji,...jk->...ik',R,T))
output.append(_np.einsum('...ji,...jk->...ik',R,T))
return tuple(output)
@ -290,12 +275,11 @@ def _Mises(T_sym,s):
Parameters
----------
T_sym : numpy.ndarray of shape (:,3,3) or (3,3)
T_sym : numpy.ndarray of shape (...,3,3)
Symmetric tensor of which the von Mises equivalent is computed.
s : float
Scaling factor (2/3 for strain, 3/2 for stress).
"""
d = deviatoric_part(T_sym)
return _np.sqrt(s*(_np.sum(d**2.0))) if _np.shape(T_sym) == (3,3) else \
_np.sqrt(s*_np.einsum('...jk->...',d**2.0))
return _np.sqrt(s*_np.einsum('...jk->...',d**2.0))