Create test_twist.py

Author: claudioperez

tests/test_twist.py

@@ -0,0 +1,101 @@
+import pytest
+
+from xsection.analysis.venant import SaintVenantSectionAnalysis 
+from xsection.library import Rectangle
+from xsection.properties import torsion_constant
+
+
+def test_T3():
+
+    shape = Rectangle(b=3, d=5, 
+                      mesh_scale=1/40,
+                      mesher="triangle",
+                      mesh_type="T3")
+    sv = SaintVenantSectionAnalysis(shape, nu=0.3)
+    assert sv._A == pytest.approx(shape.d*shape.b, rel=1e-6)
+
+    J = torsion_constant(shape)
+    assert sv.twist_rigidity() == pytest.approx(J, rel=1e-2)
+
+
+def test_T3_material():
+
+    shape = Rectangle(b=3, d=5, 
+                      mesh_scale=1/40,
+                      material={"E": 4, "G": 2},
+                      mesher="triangle",
+                      mesh_type="T3")
+    sv = SaintVenantSectionAnalysis(shape)
+    assert sv._A == pytest.approx(shape.d*shape.b, rel=1e-6)
+    assert sv._EA == pytest.approx(shape.d*shape.b*shape.material["E"], rel=1e-6)
+
+    J = torsion_constant(shape)
+    assert sv.twist_rigidity()/shape.material["G"] == pytest.approx(J, rel=1e-2)
+
+    
+
+
+def test_T6():
+    shape = Rectangle(b=3, d=5, 
+                      mesh_scale=1/5,
+                      poisson=0.3,
+                      mesher="triangle",
+                      mesh_type="T6")
+
+    sv = SaintVenantSectionAnalysis(shape, nu=0.3)
+    assert sv._A == pytest.approx(shape.d*shape.b, rel=1e-6)
+
+    J = torsion_constant(shape)
+    assert sv.torsion_constant() == pytest.approx(J, rel=1e-2)
+
+
+    ic = sv.iesan_center()
+    # print("Iesan center:", ic)
+    assert ic[0] == pytest.approx(0, abs=1e-3)
+    assert ic[1] == pytest.approx(0, abs=1e-3)
+
+
+def test_T6_gmsh():
+    from xsection.analysis.venant import SaintVenantSectionAnalysis 
+    from xsection.library import Rectangle
+    from xsection.properties import torsion_constant
+    material = {"E": 4, "G": 2}
+    shape = Rectangle(b=3, d=5,
+                      mesh_scale=1/10,
+                      material=material,
+                      mesher="gmsh",
+                      mesh_type="T6")
+    sv = SaintVenantSectionAnalysis(shape)#, nu=0.3)
+    assert sv._A == pytest.approx(shape.d*shape.b, rel=1e-6)
+
+    J = torsion_constant(shape)
+    assert sv.twist_rigidity()/material["G"] == pytest.approx(J, rel=1e-2)
+
+
+    ic = sv.iesan_center()
+    assert ic[0] == pytest.approx(0, abs=1e-3)
+    assert ic[1] == pytest.approx(0, abs=1e-3)
+
+
+def test_T6_material_gmsh():
+    from xsection.analysis.venant import SaintVenantSectionAnalysis 
+    from xsection.library import Rectangle
+    from xsection.properties import torsion_constant
+
+    shape = Rectangle(b=3, d=5,
+                      mesh_scale=1/10,
+                      material={"E": 4, "G": 2},
+                      mesher="gmsh",
+                      mesh_type="T6")
+    sv = SaintVenantSectionAnalysis(shape, nu=0.3)
+    assert sv._A == pytest.approx(shape.d*shape.b, rel=1e-6)
+    assert sv._EA == pytest.approx(shape.d*shape.b*shape.material["E"], rel=1e-6)
+    assert sv._GA == pytest.approx(shape.d*shape.b*shape.material["G"], rel=1e-6)
+
+    J = torsion_constant(shape)
+    assert sv.twist_rigidity()/shape.material["G"] == pytest.approx(J, rel=1e-2)
+
+
+    ic = sv.iesan_center()
+    assert ic[0] == pytest.approx(0, abs=1e-3)
+    assert ic[1] == pytest.approx(0, abs=1e-3)