BcManager.hpp File Reference

High-level boundary condition management interface. More...

#include "UnknownInterface.hpp"

Go to the source code of this file.

Classes
struct	MoFEM::BcMeshsetType< BC >
	Template specialization system for type-safe boundary condition handling. More...
struct	MoFEM::BcScalarMeshsetType< BC >
	Template specialization for scalar field boundary conditions. More...
struct	MoFEM::BcDisplacementMeshsetType< BC >
	Template specialization for displacement boundary conditions. More...
struct	MoFEM::BcForceMeshsetType< BC >
	Template specialization for force boundary conditions. More...
struct	MoFEM::BcFluxMeshsetType< BC >
	Template specialization for flux boundary conditions. More...
struct	MoFEM::BcNormalDisplacementMeshsetType< BC >
	Template specialization for normal displacement constraints. More...
struct	MoFEM::BcAnalyticalDisplacementMeshsetType< BC >
	Template specialization for analytical displacement functions. More...
struct	MoFEM::BcAnalyticalTractionMeshsetType< BC >
	Template specialization for analytical traction functions. More...
struct	MoFEM::BcPressureMeshsetType< BC >
	Template specialization for pressure boundary conditions. More...
struct	MoFEM::BcManager
	Boundary condition manager for finite element problem setup. More...
struct	MoFEM::BcManager::BCs
	Data structure storing boundary condition markers and attributes. More...

Namespaces
namespace	MoFEM
	implementation of Data Operators for Forces and Sources

Typedefs
template<CubitBC BC>
using	MoFEM::BcTemperature = BcScalarMeshsetType< BC >
	Type alias for temperature boundary conditions.

Detailed Description

High-level boundary condition management interface.

The BcManager provides a high-level interface for applying boundary conditions to finite element problems, working in close integration with MeshsetsManager to bridge mesh-based boundary condition definitions with finite element implementations.

MeshsetsManager Integration

BcManager operates as the application layer above MeshsetsManager:

• Data Discovery: MeshsetsManager discovers and organizes boundary condition meshsets from various mesh formats (CUBIT, Gmsh, Salome, etc.)
• DOF Management: BcManager translates meshset information into DOF-level operations for finite element problem setup
• Type Safety: Provides type-safe interfaces for different boundary condition types while maintaining format independence
• Problem Integration: Handles DOF marking, removal, and Index Set creation for seamless integration with finite element solvers

Essential vs Natural Boundary Conditions

BcManager supports both essential and natural boundary condition implementations:

Essential Boundary Conditions (Dirichlet)

• Implementation: Applied by removing constrained DOFs from the system
• DOF Removal: removeBlockDOFsOnEntities() eliminates constrained DOFs
• System Modification: Reduces system size by eliminating known DOFs
• Examples: Fixed displacements, prescribed temperatures, velocity constraints
• Workflow: Mark DOFs → Remove from system → Apply prescribed values

Natural Boundary Conditions (Neumann)

• Implementation: Applied through load vectors and surface integrals
• DOF Marking: pushMarkDOFsOnEntities() identifies affected DOFs
• Entity Access: Provides entity ranges for integration operations
• Examples: Applied forces, pressure loads, heat flux, traction boundaries
• Workflow: Mark DOFs → Integrate over boundaries → Add to load vector

Template Specializations

BcManager uses template specializations to handle different boundary condition types and meshset configurations in a type-safe manner:

Meshset Type Specializations

• BcMeshsetType<DISPLACEMENTSET>: Displacement boundary conditions on nodesets
• BcMeshsetType<FORCESET>: Force boundary conditions on nodesets
• BcMeshsetType<TEMPERATURESET>: Temperature boundary conditions on nodesets
• BcMeshsetType<HEATFLUXSET>: Heat flux boundary conditions on sidesets
• BcMeshsetType<PRESSURESET>: Pressure boundary conditions on sidesets

Block-Based Specializations

• BcDisplacementMeshsetType<BLOCKSET>: Volume-based displacement constraints
• BcScalarMeshsetType<BLOCKSET>: Volume-based scalar field constraints
• BcForceMeshsetType<BLOCKSET>: Volume-based force application
• BcPressureMeshsetType<BLOCKSET>: Volume-based pressure conditions
• BcNormalDisplacementMeshsetType<BLOCKSET>: Normal displacement constraints
• BcAnalyticalDisplacementMeshsetType<BLOCKSET>: Analytical displacement functions
• BcAnalyticalTractionMeshsetType<BLOCKSET>: Analytical traction functions

Data Structure Specializations

• DisplacementCubitBcData: CUBIT displacement boundary condition data
• TemperatureCubitBcData: CUBIT temperature boundary condition data
• HeatFluxCubitBcData: CUBIT heat flux boundary condition data
• ForceCubitBcData: CUBIT force boundary condition data
• PressureCubitBcData: CUBIT pressure boundary condition data

Purpose of Specializations

Type Safety and Compile-Time Checking

The template specialization system provides several critical benefits:

1. Geometric Entity Differentiation (NODESET vs SIDESET vs BLOCKSET):

• NODESET (0D): Point-based boundary conditions applied to mesh vertices
  • Essential: Dirichlet constraints removing DOF degrees of freedom
  • Natural: Concentrated loads applied at specific points
• SIDESET (2D): Surface-based boundary conditions applied to mesh faces
  • Essential: Surface-distributed constraints (e.g., zero normal displacement)
  • Natural: Pressure loads, heat flux, traction forces requiring surface integration
• BLOCKSET (3D): Volume-based constraints and body forces applied to mesh regions
  • Essential: Domain-wide field constraints and material property assignments
  • Natural: Body forces, heat sources, manufacturing forces within volumes

2. Physics-Specific Type Safety:

• DisplacementCubitBcData: Vector fields with 3 spatial components (Ux, Uy, Uz)
• TemperatureCubitBcData: Scalar field with single temperature value
• ForceCubitBcData: Vector loading with force magnitude and direction
• PressureCubitBcData: Scalar pressure with automatic normal direction calculation
• HeatFluxCubitBcData: Scalar flux with surface orientation handling

3. Compile-Time Dispatch Benefits:

• Prevents runtime errors by catching type mismatches during compilation
• Enables optimized code generation for each boundary condition type
• Provides clear separation between essential (constraint) and natural (loading) operations
• Allows physics-specific validation and error checking

4. Essential vs Natural BC Implementation Patterns:

// Essential BC Pattern (DOF removal):
bc_manager.removeBlockDOFsOnEntities<BcMeshsetType<DISPLACEMENTSET>>(
    "problem", "DISPLACEMENT", true, false, false);
 
// Natural BC Pattern (DOF marking for integration):
bc_manager.pushMarkDOFsOnEntities<BcMeshsetType<FORCESET>>(
    "problem", "DISPLACEMENT", true, false);

5. BLOCKSET Specializations for Advanced Physics:

• Volume Constraints: Entire material regions with uniform properties
• Body Forces: Gravitational, centrifugal, or manufacturing loads
• Material Interfaces: Coupling between different physics domains
• Analytical Functions: Mathematical expressions for complex loading patterns
• Multi-Physics Coupling: Temperature-dependent displacement constraints

Geometry-Specific Handling

• NODESET Operations: Point-based constraints and loads (0D entities)
• SIDESET Operations: Surface-based conditions and fluxes (2D entities)
• BLOCKSET Operations: Volume-based constraints and body forces (3D entities)
• Bridge Dimensions: Proper handling of DOF-to-geometry associations

Physics-Specific Implementations

• Mechanical: Displacement, force, pressure, traction boundary conditions
• Thermal: Temperature and heat flux boundary conditions
• Multi-Physics: Coupled boundary condition handling across physics domains
• Analytical: Mathematical function-based boundary condition application

Typical Workflow

1. Mesh Loading: MeshsetsManager discovers boundary condition meshsets
2. BC Detection: BcManager identifies available boundary condition types
3. Essential BCs: Remove constrained DOFs using removeBlockDOFsOnEntities()
4. Natural BCs: Mark affected DOFs using pushMarkDOFsOnEntities()

Definition in file BcManager.hpp.