mirror of
https://github.com/JuliaFEM/JuliaFEM.jl.git
synced 2026-09-20 01:59:59 +00:00
Jukka Aho
53 lines
1.4 KiB
Julia
53 lines
1.4 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 <: Equation
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get_unknown_field_name(eq::DirichletEquation) = symbol("reaction force")
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### Dirichlet problem + equations
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type DirichletProblem <: BoundaryProblem
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equations :: Array{DirichletEquation, 1}
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end
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function DirichletProblem()
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DirichletProblem([])
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end
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get_dimension(pr::Type{DirichletProblem}) = 1 # ..?
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get_equation(pr::Type{DirichletProblem}, el::Type{Seg2}) = DBC2D2
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"""
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Dirichlet boundary condition element for 2 node line segment
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"""
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type DBC2D2 <: DirichletEquation
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element :: Seg2
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integration_points :: Array{IntegrationPoint, 1}
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global_dofs :: Array{Int64, 1}
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fieldval :: Function
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end
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function DBC2D2(element::Seg2)
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integration_points = [
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IntegrationPoint([-sqrt(1/3)], 1.0),
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IntegrationPoint([+sqrt(1/3)], 1.0)]
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push!(element, FieldSet("reaction force"))
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fieldval(X, t) = 0.0
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DBC2D2(element, integration_points, [], fieldval)
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end
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function get_lhs(eq::DBC2D2, ip, t)
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el = get_element(eq)
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h = get_basis(el)(ip.xi)
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return h*h'
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end
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function get_rhs(eq::DBC2D2, ip, t)
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el = get_element(eq)
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h = get_basis(el, ip.xi)
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f = eq.fieldval
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X = interpolate(el, "geometry", ip.xi, t)
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return h*f(X, t)
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end
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has_lhs(eq::DBC2D2) = true
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has_rhs(eq::DBC2D2) = true
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