mirror of
https://github.com/JuliaFEM/JuliaFEM.jl.git
synced 2026-09-10 13:17:42 +00:00
Jukka Aho
83 lines
2.4 KiB
Julia
83 lines
2.4 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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# Dirichlet boundary conditions in weak form
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abstract DirichletEquation <: BoundaryEquation
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### Dirichlet problem + equations
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type DirichletProblem <: BoundaryProblem
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unknown_field_name :: ASCIIString
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unknown_field_dimension :: Int
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equations :: Vector{DirichletEquation}
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end
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""" Initialize new Dirichlet boundary condition.
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Parameters
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----------
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dimension
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dimension of unknown field (scalar, vector, ...)
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Examples
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--------
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"""
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function DirichletProblem(unknown_field_name::ASCIIString, dimension::Int=1)
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DirichletProblem(unknown_field_name, dimension, [])
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end
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""" Dirichlet boundary condition element for 2 node line segment """
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type DBC2D2 <: DirichletEquation
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element :: Seg2
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integration_points :: Vector{IntegrationPoint}
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end
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function Base.size(equation::DBC2D2)
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return (1, 2)
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end
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function Base.convert(::Type{DirichletEquation}, element::Seg2)
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integration_points = line3()
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haskey(element, "reaction force") || (element["reaction force"] = 0.0 => zeros(2))
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DBC2D2(element, integration_points)
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end
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function assemble!(assembly::Assembly, equation::DirichletEquation, time::Number=0.0, problem=nothing)
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isa(problem, Void) && error("Dicihlet boundary condition needs problem defined")
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field_dim = problem.unknown_field_dimension
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field_name = problem.unknown_field_name
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element = get_element(equation)
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gdofs = get_gdofs(element, field_dim)
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basis = get_basis(element)
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detJ = det(basis)
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for ip in get_integration_points(equation)
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w = ip.weight * detJ(ip)
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N = basis(ip, time)
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A = w*N'*N
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if haskey(element, field_name)
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# add all dimensions at once
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for i=1:field_dim
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g = element(field_name, ip, time)
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ldofs = gdofs[i:field_dim:end]
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add!(assembly.stiffness_matrix, ldofs, ldofs, A)
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add!(assembly.force_vector, ldofs, w*g*N')
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end
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end
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for i=1:field_dim
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if haskey(element, field_name*" $i")
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# add single component
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g = element(field_name*" $i", ip, time)
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ldofs = gdofs[i:field_dim:end]
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add!(assembly.stiffness_matrix, ldofs, ldofs, A)
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add!(assembly.force_vector, ldofs, w*g*N')
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end
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end
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end
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end
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