From e96eb55edd226383b20eb21506a26db039707bcb Mon Sep 17 00:00:00 2001 From: Martin Diehl Date: Mon, 30 Sep 2019 14:28:58 -0700 Subject: [PATCH] calculate different strain tensors --- python/damask/dadf5.py | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/python/damask/dadf5.py b/python/damask/dadf5.py index 7363f3da1..c326002dc 100644 --- a/python/damask/dadf5.py +++ b/python/damask/dadf5.py @@ -554,7 +554,7 @@ class DADF5(): self.__add_generic_pointwise(calculation,requested,pass_through) - def add_strain_tensor(self,t,ord,defgrad='F'): #ToDo: Use t and ord + def add_strain_tensor(self,t,ord,defgrad='F'): """ Adds the a strain tensor. @@ -570,21 +570,28 @@ class DADF5(): 'V#Green':lambda V: np.broadcast_to(np.ones(3),[V.shape[0],3]) - 1.0/V**2, 'U#Green':lambda U: U**2 - np.broadcast_to(np.ones(3),[U.shape[0],3]), } + if t.lower() in ['l','left']: + stretch = 'V' + elif t.lower() in ['r','right']: + stretch = 'U' + else: + raise KeyError (U,S,Vh) = np.linalg.svd(defgrad['data']) # singular value decomposition R_inv = np.transpose(np.matmul(U,Vh),(0,2,1)) # transposed rotation of polar decomposition - U = np.matmul(R_inv,defgrad['data']) # F = RU - (D,V) = np.linalg.eigh((U+np.transpose(U,(0,2,1)))*.5) # eigen decomposition (of symmetric(ed) matrix) + s = np.matmul(R_inv,defgrad['data']) if stretch == 'U' else \ + np.matmul(defgrad['data'],R_inv) + (D,V) = np.linalg.eigh((s+np.transpose(s,(0,2,1)))*.5) # eigen decomposition (of symmetric(ed) matrix) - d = operator['V#ln'](D) + d = operator[stretch+'#'+{0:'ln',1:'Biot',2:'Green'}[ord]](D) a = np.matmul(V,np.einsum('ij,ikj->ijk',d,V)) return { 'data' : a, - 'label' : 'ln(V)({})'.format(defgrad['label']), + 'label' : 'epsilon_{}^{}({})'.format(stretch,ord,defgrad['label']), 'meta' : { 'Unit' : defgrad['meta']['Unit'], - 'Description' : 'Strain tensor ln(V){} ({})'.format(defgrad['label'],defgrad['meta']['Description']), + 'Description' : 'Strain tensor of {} ({})'.format(defgrad['label'],defgrad['meta']['Description']), 'Creator' : 'dadf5.py:add_strain_tensor v{}'.format(version) } }