testing mechanics module with pytest

python/tests/test_mechanics.py

@@ -0,0 +1,135 @@
+import numpy as np
+from damask import mechanics
+
+class TestMechanics:
+   
+    n = 9
+    c = np.random.randint(n)
+   
+
+    def test_vectorize_Cauchy(self):
+         P = np.random.random((self.n,3,3))
+         F = np.random.random((self.n,3,3))
+         assert np.allclose(mechanics.Cauchy(F,P)[self.c],
+                            mechanics.Cauchy(F[self.c],P[self.c]))
+
+
+    def test_vectorize_strain_tensor(self):
+         F = np.random.random((self.n,3,3))
+         t = ['V','U'][np.random.randint(0,2)]
+         m = np.random.random()*10. -5.0
+         assert np.allclose(mechanics.strain_tensor(F,t,m)[self.c],
+                            mechanics.strain_tensor(F[self.c],t,m))
+
+
+    def test_vectorize_deviatoric_part(self):
+         x = np.random.random((self.n,3,3))
+         assert np.allclose(mechanics.deviatoric_part(x)[self.c],
+                            mechanics.deviatoric_part(x[self.c]))
+
+
+    def test_vectorize_spherical_part(self):
+         x = np.random.random((self.n,3,3))
+         assert np.allclose(mechanics.spherical_part(x)[self.c],
+                            mechanics.spherical_part(x[self.c]))
+
+
+    def test_vectorize_Mises_stress(self):
+         sigma = np.random.random((self.n,3,3))
+         assert np.allclose(mechanics.Mises_stress(sigma)[self.c],
+                            mechanics.Mises_stress(sigma[self.c]))
+
+
+    def test_vectorize_Mises_strain(self):
+         epsilon = np.random.random((self.n,3,3))
+         assert np.allclose(mechanics.Mises_strain(epsilon)[self.c],
+                            mechanics.Mises_strain(epsilon[self.c]))
+
+
+    def test_vectorize_symmetric(self):
+         x = np.random.random((self.n,3,3))
+         assert np.allclose(mechanics.symmetric(x)[self.c],
+                            mechanics.symmetric(x[self.c]))
+
+
+    def test_vectorize_maximum_shear(self):
+         x = np.random.random((self.n,3,3))
+         assert np.allclose(mechanics.maximum_shear(x)[self.c],
+                            mechanics.maximum_shear(x[self.c]))
+
+
+    def test_vectorize_principal_components(self):
+         x = np.random.random((self.n,3,3))
+         assert np.allclose(mechanics.principal_components(x)[self.c],
+                            mechanics.principal_components(x[self.c]))
+
+
+    def test_vectorize_transpose(self):
+         x = np.random.random((self.n,3,3))
+         assert np.allclose(mechanics.transpose(x)[self.c],
+                            mechanics.transpose(x[self.c]))
+
+
+    def test_vectorize_rotational_part(self):
+         x = np.random.random((self.n,3,3))
+         assert np.allclose(mechanics.rotational_part(x)[self.c],
+                            mechanics.rotational_part(x[self.c]))
+
+
+    def test_vectorize_left_stretch(self):
+         x = np.random.random((self.n,3,3))
+         assert np.allclose(mechanics.left_stretch(x)[self.c],
+                            mechanics.left_stretch(x[self.c]))
+
+
+    def test_vectorize_right_stretch(self):
+         x = np.random.random((self.n,3,3))
+         assert np.allclose(mechanics.right_stretch(x)[self.c],
+                            mechanics.right_stretch(x[self.c]))
+
+
+    def test_Cauchy(self):
+         """Ensure Cauchy stress is symmetrized 1. Piola-Kirchhoff stress for no deformation."""
+         P = np.random.random((self.n,3,3))
+         assert np.allclose(mechanics.Cauchy(np.broadcast_to(np.eye(3),(self.n,3,3)),P),
+                            mechanics.symmetric(P))
+
+
+    def test_strain_tensor_no_rotation(self):
+         """Ensure that left and right stretch give same results for no rotation."""
+         F = np.broadcast_to(np.eye(3),[self.n,3,3])*np.random.random((self.n,3,3))
+         m = np.random.random()*20.0-10.0
+         assert np.allclose(mechanics.strain_tensor(F,'U',m),
+                            mechanics.strain_tensor(F,'V',m))
+   
+
+    def test_strain_tensor_rotation(self):
+         """Ensure that pure rotation results in no strain."""
+         F = mechanics.rotational_part(np.random.random((self.n,3,3)))
+         t = ['V','U'][np.random.randint(0,2)]
+         m = np.random.random()*2.0 - 1.0
+         assert np.allclose(mechanics.strain_tensor(F,t,m),
+                            0.0)
+   
+
+    def test_spherical_deviatoric_part(self):
+         """Ensure that full tensor is sum of spherical and deviatoric part."""
+         x = np.random.random((self.n,3,3))
+         sph = np.broadcast_to(np.eye(3),(self.n,3,3))\
+             * np.repeat(mechanics.spherical_part(x),9).reshape(self.n,3,3)
+         assert np.allclose(sph + mechanics.deviatoric_part(x),
+                            x)
+
+
+    def test_symmetric(self):
+         """Ensure that a symmetric tensor is half of the sum of a tensor and its transpose."""
+         x = np.random.random((self.n,3,3))
+         assert np.allclose(mechanics.symmetric(x)*2.0,
+                            mechanics.transpose(x)+x)
+
+
+    def test_transpose(self):
+         """Ensure that a symmetric tensor equals its transpose."""
+         x = mechanics.symmetric(np.random.random((self.n,3,3)))
+         assert np.allclose(mechanics.transpose(x),
+                            x)