Add enum for strong and weak enforcement

Author: ttruster

include/base/periodic_boundary_base.h

@@ -38,6 +38,13 @@ namespace libMesh
 class Elem;
 class MeshBase;
 
+/**
+ * The type of enforcement of condition; strong(default) = constraint matrix
+ */
+enum class EnforcementType
+  { STRONG_ENFORCEMENT=0,
+    WEAK_ENFORCEMENT=1 };
+
 /**
  * The base class for defining periodic boundaries.
  *
@@ -126,6 +133,16 @@ class PeriodicBoundaryBase
    */
   const std::set<unsigned int> & get_variables() const;
 
+  /**
+   * Get the enforcement type.
+   */
+  const EnforcementType & get_enforcement_type() const;
+
+  /**
+   * Set the enforcement type.
+   */
+  void set_enforcement_type(const EnforcementType & e_type);
+
 protected:
 
   /**
@@ -145,6 +162,8 @@ class PeriodicBoundaryBase
    */
   std::unique_ptr<DenseMatrix<Real>> _transformation_matrix;
 
+  EnforcementType _enforcement_type;
+
 };
 
 } // namespace libmesh

src/base/periodic_boundary_base.C

@@ -111,6 +111,18 @@ const std::set<unsigned int> & PeriodicBoundaryBase::get_variables() const
   return variables;
 }
 
+
+const EnforcementType & PeriodicBoundaryBase::get_enforcement_type() const
+{
+  return _enforcement_type;
+}
+
+
+void PeriodicBoundaryBase::set_enforcement_type(const EnforcementType & e_type)
+{
+  this->_enforcement_type = e_type;
+}
+
 } // namespace libMesh
 
 #endif // LIBMESH_ENABLE_PERIODIC

src/fe/fe_base.C

@@ -1928,7 +1928,7 @@ compute_periodic_constraints (DofConstraints & constraints,
       for (const auto & boundary_id : bc_ids)
         {
           const PeriodicBoundaryBase * periodic = boundaries.boundary(boundary_id);
-          if (!periodic || !periodic->is_my_variable(variable_number))
+          if (!periodic || !periodic->is_my_variable(variable_number) || (periodic->get_enforcement_type()==EnforcementType::WEAK_ENFORCEMENT))
             continue;
 
           libmesh_assert(point_locator);