mirror of
https://github.com/JuliaFEM/JuliaFEM.jl.git
synced 2026-10-02 06:13:59 +00:00
Jukka Aho
ae9e7e3727
- Implement add_dirichlet! for essential BCs (prescribed values) - Implement add_neumann! for natural BCs (forces/tractions) - Support multiple nodes and DOF components in single call - Store BCs in physics.bc_dirichlet and physics.bc_neumann - Add usage examples for common BC patterns - 86 lines with complete method implementations
87 lines
2.6 KiB
Julia
87 lines
2.6 KiB
Julia
# This file is a part of JuliaFEM.
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# License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
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"""
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Boundary condition implementations for Physics.
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This file provides concrete implementations of the boundary condition interface
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functions defined in `src/physics/api.jl` for the `Physics` type.
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"""
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# ============================================================================
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# BOUNDARY CONDITION METHODS (implement generic API)
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# ============================================================================
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"""
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add_dirichlet!(physics::Physics, node_ids::Vector{Int}, components::Vector{Int}, value::Float64)
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Concrete implementation of Dirichlet BC application.
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Applies essential (prescribed) boundary conditions to specified nodes and DOF components.
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# Arguments
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- `physics::Physics`: Physics problem
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- `node_ids::Vector{Int}`: Node IDs where BC applies
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- `components::Vector{Int}`: Which DOF components (e.g., [1,2,3] for all, [3] for z-direction)
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- `value::Float64`: Prescribed value
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# Examples
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```julia
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# Fix all DOFs at nodes 1, 2, 3
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add_dirichlet!(physics, [1,2,3], [1,2,3], 0.0)
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# Fix only z-displacement at node 10
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add_dirichlet!(physics, [10], [3], 0.0)
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# Prescribe x-displacement at node 20
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add_dirichlet!(physics, [20], [1], 0.1)
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```
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See generic documentation in `src/physics/api.jl`.
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"""
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function add_dirichlet!(physics::Physics, node_ids::Vector{Int}, components::Vector{Int}, value::Float64)
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bc = physics.bc_dirichlet
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for node in node_ids
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push!(bc.node_ids, node)
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push!(bc.components, components)
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push!(bc.values, value)
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end
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return nothing
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end
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"""
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add_neumann!(physics::Physics, surface_ids::Vector{Int}, traction::Vec{3,Float64})
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Concrete implementation of Neumann BC application.
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Applies natural (force/traction) boundary conditions to specified surfaces.
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# Arguments
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- `physics::Physics`: Physics problem
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- `surface_ids::Vector{Int}`: Surface/edge element IDs where BC applies
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- `traction::Vec{3,Float64}`: Traction vector
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# Examples
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```julia
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# Apply traction to surface
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traction = Vec{3}(0.0, -1000.0, 0.0) # 1000 N/m² downward
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add_neumann!(physics, surface_elements, traction)
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# Apply force to individual nodes (surface_ids are node IDs in this case)
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force = Vec{3}(0.0, -100.0, 0.0) # 100 N downward
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add_neumann!(physics, loaded_nodes, force)
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```
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See generic documentation in `src/physics/api.jl`.
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"""
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function add_neumann!(physics::Physics, surface_ids::Vector{Int}, traction::Vec{3,Float64})
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bc = physics.bc_neumann
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for surf in surface_ids
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push!(bc.surface_ids, surf)
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push!(bc.values, traction)
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end
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return nothing
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end
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