add test, format black

src/felupe/mechanics/_solidbody.py

@@ -398,13 +398,13 @@ def _cauchy_stress(self, field=None):
         return dot(P, transpose(F)) / J
 
     def _mass(self, density=None):
-        
+
         if density is None:
             density = self.density
-        
+
         field = self.field[0].as_container()
         dim = field[0].dim
-        
+
         form = self._form(
             fun=[density * np.eye(dim).reshape(dim, dim, 1, 1)],
             v=field,
@@ -413,5 +413,5 @@ def _mass(self, density=None):
             grad_v=[False],
             grad_u=[False],
         )
-        
+
         return form.assemble()

tests/test_free_vibration.py

@@ -4,6 +4,20 @@
 
 
 def test_free_vibration():
+
+    mesh = fem.Cube(a=(0, 0, 5), b=(50, 100, 30), n=(3, 6, 4))
+    region = fem.RegionHexahedron(mesh)
+    field = fem.FieldContainer([fem.Field(region, dim=3)])
+
+    umat = fem.NeoHooke(mu=1, bulk=2)
+    solid = fem.SolidBody(umat=umat, field=field, density=1.5e-9)
+
+    job = fem.FreeVibration([solid]).evaluate(x0=field)
+    new_field, frequency = job.extract(x0=field, n=-1, inplace=False)
+
+
+def test_free_vibration_mixed():
+
     meshes = [
         fem.Cube(a=(0, 0, 30), b=(50, 100, 35), n=(3, 6, 2)),
         fem.Cube(a=(0, 0, 5), b=(50, 100, 30), n=(3, 6, 4)),
@@ -34,8 +48,7 @@ def test_free_vibration():
     job = fem.FreeVibration(solids, boundaries).evaluate(x0=field)
     new_field, frequency = job.extract(x0=field, n=-1, inplace=False)
 
-    assert np.isclose(new_field[0].values.max(), 358.08157)
-
 
 if __name__ == "__main__":
     test_free_vibration()
+    test_free_vibration_mixed()

tests/test_mechanics.py

@@ -235,7 +235,11 @@ def test_solidbody_incompressible():
 
     umat = fem.OgdenRoxburgh(fem.NeoHooke(mu=1), r=3, m=1, beta=0)
     b = fem.SolidBodyNearlyIncompressible(
-        umat=umat, field=u, bulk=5000, state=fem.StateNearlyIncompressible(u), density=1.0
+        umat=umat,
+        field=u,
+        bulk=5000,
+        state=fem.StateNearlyIncompressible(u),
+        density=1.0,
     )
 
     M = b.assemble.mass()