Adding element offsets to shell and beam elements (#250)

* Adding thickness offset option to iso shell constitutive

* Adding thickness offset option to composite shell constitutive

* Fixing problem in generateBDFCard

* Fixing problem in generateBDFCard

* Adding thickness offset to smeared composite class

* Adding thickness offset to smeared rectangular beam class

* Fixing broken test

* test debug

* reducing real tolerance for failing test

* Adding offset terms to shell inertia

* clang format

* Initialization bug fix

* Minor comment edit

* Adding offset terms to beam inertia

* Adding beam offset integration test

* Moving beam transform to separate header file

* Updating test docstring

* Adding plate offset integration test

* Adding additional docstrings to offset parameters

* Updating include statement in cython file to reflect new beam transfer header

* Minor comment edit

* Fixing index in smeared composite mass moment

* Fixing bugs in offset routine for smeared composite

* Fixing bugs in dv sens for shell moment of inertia

* Adding more offset tests

* clang format

* Fixing sign issue on shell moment term

* Fixing sign issue on beam mass moment terms

* clang format

* switching from cte to alpha kwargs

* Adding missing quadrature weight to beam inertial force

* clang format

* Adding mass moment to centrifugal force

* Adding centrifugal offset test to shell integration test

src/constitutive/TACSBasicBeamConstitutive.cpp

@@ -122,7 +122,7 @@ TACSBasicBeamConstitutive::TACSBasicBeamConstitutive(
   C[0] = E * A;
   C[6] = G * J;
   C[11] = E * Iz;
-  C[12] = E * Iyz;
+  C[12] = -E * Iyz;
   C[15] = E * Iy;
   C[18] = ky * G * A;
   C[20] = kz * G * A;
@@ -131,9 +131,9 @@ TACSBasicBeamConstitutive::TACSBasicBeamConstitutive(
   rho[0] = density * A;
   rho[1] = 0.0;
   rho[2] = 0.0;
-  rho[3] = density * Iy;
-  rho[4] = density * Iz;
-  rho[5] = density * Iyz;
+  rho[3] = density * Iz;
+  rho[4] = density * Iy;
+  rho[5] = -density * Iyz;
 }
 
 TACSBasicBeamConstitutive::~TACSBasicBeamConstitutive() {

src/constitutive/TACSCompositeShellConstitutive.cpp

@@ -27,7 +27,7 @@ const char *TACSCompositeShellConstitutive::constName =
 TACSCompositeShellConstitutive::TACSCompositeShellConstitutive(
     int _num_plies, TACSOrthotropicPly **_ply_props,
     const TacsScalar *_ply_thickness, const TacsScalar *_ply_angles,
-    TacsScalar _kcorr) {
+    TacsScalar _kcorr, TacsScalar _tOffset) {
   num_plies = _num_plies;
   ply_thickness = new TacsScalar[num_plies];
   ply_angles = new TacsScalar[num_plies];
@@ -42,6 +42,7 @@ TACSCompositeShellConstitutive::TACSCompositeShellConstitutive(
   }
 
   kcorr = _kcorr;
+  tOffset = _tOffset;
 }
 
 TACSCompositeShellConstitutive::~TACSCompositeShellConstitutive() {
@@ -83,7 +84,7 @@ void TACSCompositeShellConstitutive::evalMassMoments(int elemIndex,
   }
 
   // Compute the contribution to the mass moment from each layer
-  TacsScalar t0 = -0.5 * t;
+  TacsScalar t0 = -(0.5 + tOffset) * t;
   for (int i = 0; i < num_plies; i++) {
     TacsScalar rho_ply = ply_props[i]->getDensity();
     TacsScalar t1 = t0 + ply_thickness[i];
@@ -131,7 +132,7 @@ void TACSCompositeShellConstitutive::evalStress(int elemIndex,
   }
 
   // Compute the contribution to the stiffness from each layer
-  TacsScalar t0 = -0.5 * t;
+  TacsScalar t0 = -(0.5 + tOffset) * t;
   for (int k = 0; k < num_plies; k++) {
     TacsScalar Qbar[6], Abar[3];
     ply_props[k]->calculateQbar(ply_angles[k], Qbar);
@@ -174,7 +175,7 @@ TacsScalar TACSCompositeShellConstitutive::evalFailure(
   for (int i = 0; i < num_plies; i++) {
     t += ply_thickness[i];
   }
-  TacsScalar t0 = -0.5 * t;
+  TacsScalar t0 = -(0.5 + tOffset) * t;
 
   // Keep track of the maximum failure criterion
   TacsScalar max = 0.0;
@@ -207,7 +208,7 @@ TacsScalar TACSCompositeShellConstitutive::evalFailureStrainSens(
   for (int i = 0; i < num_plies; i++) {
     t += ply_thickness[i];
   }
-  TacsScalar t0 = -0.5 * t;
+  TacsScalar t0 = -(0.5 + tOffset) * t;
 
   // Keep track of the maximum failure criterion
   TacsScalar max = 0.0;
@@ -270,7 +271,7 @@ void TACSCompositeShellConstitutive::evalTangentStiffness(int elemIndex,
   }
 
   // Compute the contribution to the stiffness from each layer
-  TacsScalar t0 = -0.5 * t;
+  TacsScalar t0 = -(0.5 + tOffset) * t;
   for (int k = 0; k < num_plies; k++) {
     TacsScalar Qbar[6], Abar[3];
     ply_props[k]->calculateQbar(ply_angles[k], Qbar);
@@ -353,3 +354,10 @@ void TACSCompositeShellConstitutive::getPlyAngles(TacsScalar *_ply_angles) {
     _ply_angles[i] = ply_angles[i];
   }
 }
+
+/*
+  Get thickness offset
+*/
+TacsScalar TACSCompositeShellConstitutive::getThicknessOffset() {
+  return tOffset;
+}

src/constitutive/TACSCompositeShellConstitutive.h

@@ -28,7 +28,8 @@ class TACSCompositeShellConstitutive : public TACSShellConstitutive {
                                  TACSOrthotropicPly **_ply_props,
                                  const TacsScalar *_ply_thickness,
                                  const TacsScalar *_ply_angles,
-                                 TacsScalar _kcorr = 5.0 / 6.0);
+                                 TacsScalar _kcorr = 5.0 / 6.0,
+                                 TacsScalar _tOffset = 0.0);
   ~TACSCompositeShellConstitutive();
 
   // Evaluate the material density
@@ -78,13 +79,14 @@ class TACSCompositeShellConstitutive : public TACSShellConstitutive {
   // Get ply angles and thicknesses
   void getPlyThicknesses(TacsScalar *_ply_thickness);
   void getPlyAngles(TacsScalar *_ply_angles);
+  TacsScalar getThicknessOffset();
 
  private:
   // Store information about the design variable
   int num_plies;
   TACSOrthotropicPly **ply_props;
   TacsScalar *ply_thickness, *ply_angles;
-  TacsScalar kcorr;
+  TacsScalar kcorr, tOffset;
 
   // The object name
   static const char *constName;