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JuliaFEM.jl/src/solver_utils.jl
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2016-06-25 04:12:53 +03:00

346 lines
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Julia

# This file is a part of JuliaFEM.
# License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
function subscript(i)
map(repr(i)) do c
c == '1' ? '\u2081' :
c == '2' ? '\u2082' :
c == '3' ? '\u2083' :
c == '4' ? '\u2084' :
c == '5' ? '\u2085' :
c == '6' ? '\u2086' :
c == '7' ? '\u2087' :
c == '8' ? '\u2088' :
c == '9' ? '\u2089' :
c == '0' ? '\u2080' :
error("Unexpected character")
end
end
function pretty_print_constraint_equation(a, b, g; char1="u", char2="λ")
s = ""
for (i, c) in enumerate(find(a))
if (i != 1)
s = s * ((a[c] < 0) ? " - " : " + ")
end
s = s*"$(round(abs(a[c]), 3))*$char1$(subscript(c))"
end
for (i, c) in enumerate(find(b))
if (length(find(a)) != 0) || (i != 1)
s = s * ((b[c] < 0) ? " - " : " + ")
end
s = s*"$(round(abs(b[c]), 3))*$char2$(subscript(c))"
end
s = s * " = $(round(g, 3))"
s
end
function pretty_print_C1_row(r)
s = ""
for a in find(r)
c = r[a] < 0 ? "-" : "+"
s = s * "$c $(round(abs(r[a]), 3))$(subscript(a)) "
end
s = s * ""
return s
end
function handle_overconstraint_error!(problem, nodes, all_dofs, C1_, C1, C2_, C2, D_, D, g_, g; show_info=false)
# old, new, old, new...
#= herzian contact with symmetry boundary
# INFO: SUMMARY for node id 555 with dofs 1109, 1110:
# INFO: ----- Current constraint -----
# INFO: lambda coefficients in C1 matrix are:
# INFO: dof 1109: + 0.15*λ
# INFO: rows in constraint matrix C2 & D
# INFO: dof 1109: 0.15*u = -0.0 <-- overconstrained dof
# INFO: ----- New constraint -----
# INFO: lambda coefficients in C1 matrix are:
# INFO: dof 1109: + 0.15*λ
# INFO: dof 1110: + 0.15*λ
# INFO: rows in constraint matrix C2 & D
# INFO: dof 1109: 0.0*u - 0.0*u - 0.0*u + 0.15*u + 0.0*u - 0.15*u = -0.0 <-- overconstrained dof
# INFO: dof 1110: 0.15*λ + 0.0*λ = -0.0
# INFO: ----- Related equations -----
# INFO: dof 1110: 0.15*λ + 0.0*λ = -0.0
# INFO: dof 155: 0.165*u = 0.0
# INFO: algorithm 1 solved issue? false
# INFO: algorithm 2 solved issue? true
# INFO: fixed: new setting is
# INFO: dof 1109: 0.0*u - 0.0*u - 0.0*u + 0.15*u + 0.0*u - 0.15*u = -0.0
=#
#=
if 555 in nodes
info("overconstraint DIRTY HACK")
# It is possible to selectively remove mortar constraints and the associated
# Lagrange multiplier components in certain axis directions and replace them
# with the Dirichlet (symmetry) conditions.
# old configuration is dirichlet symmetry condition
# new configuration is mortar constraint
# 1. remove mortar constrains and associated Lagrange multiplier components
# in dof 1109, that is, x direction of node 555.
# works quite well
# C1_[1109,:] = 0
# C2_[1110,:] = C2_[1109,:]
# C2[1110,:] = 0
# D[1110,:] = 0
#C1_[1110,:] = C1_[1109,:]
C2_[1110,:] = C2_[1109,:]
#C1_[1109,:] = 0
C2_[1109,:] = 0
#C1[1110,:] = 0
#C2[1110,:] = 0
#C2[:,1109] = 0
D[1110,:] = 0
#D[:,1109] = 0
g[1110,:] = 0
#D[:,1109] = 0
#C2[:,1109] = 0
#C1[1109,:] = 0
#C1_[1110,:] = 0
return
end
=#
""" Return all other dofs which connects to overconstrained dofs. """
function get_related_dofs(dofs)
dofs_ = Set(dofs)
for dof in copy(dofs_)
c = find(C2[dof,:])
length(c) != 0 && push!(dofs_, c...)
c = find(C2_[dof,:])
length(c) != 0 && push!(dofs_, c...)
end
for dof in copy(dofs_)
c = find(C2[dof,:])
length(c) != 0 && push!(dofs_, c...)
c = find(C2_[dof,:])
length(c) != 0 && push!(dofs_, c...)
end
for dof in copy(dofs_)
c = find(C2[dof,:])
length(c) != 0 && push!(dofs_, c...)
c = find(C2_[dof,:])
length(c) != 0 && push!(dofs_, c...)
end
dofs_ = sort(collect(dofs_))
return dofs_
end
""" Return true if dofs has lagrange coefficients, i.e. D is nonzero. """
function has_lagrange_coefficients(dof::Int)
return (countnz(D[dof, :]) != 0) || (countnz(D_[dof, :]) != 0)
end
function has_lagrange_coefficients(dofs::Vector{Int})
return map(has_lagrange_coefficients, dofs)
end
""" Test is dof single point constraint. """
function is_spc(C, dof)
return countnz(C[dof, :]) == 1
end
function is_spc(dof::Int)
return is_spc(C2, dof) && is_spc(C2_, dof)
end
function is_spc(dofs::Vector{Int})
return map(is_spc, dofs)
end
function has_anything(dof::Int)
countnz(C1[dof,:]) != 0 && return true
countnz(C2[dof,:]) != 0 && return true
countnz(D[dof,:]) != 0 && return true
countnz(g[dof,:]) != 0 && return true
return false
end
""" Algorithm 1. Calculate rank of overdetermined system and do LSQ if
rank(C) equals to number of unique dofs.
"""
function action1(node_id, dofs)
dofs_ = get_related_dofs(intersect(dofs, all_dofs))
# this will fail with dofs > 2 for some yet unknown reason
length(dofs_) > 2 && return dofs_, false
any(has_lagrange_coefficients(dofs_)) && return dofs_, false
C = full([C2[dofs_, :]; C2_[dofs_, :]])
d = full([g[dofs_]; g_[dofs_]])
info("rank = $(rank(C)), dofs = $(length(dofs_))")
rank(C) != length(dofs_) && return dofs_, false
C2_[dofs_,:] = C2[dofs_,:] = 0
g_[dofs_,:] = g[dofs_,:] = 0
x = C \ d
C2[dofs_, dofs_] = eye(length(dofs_))
g[dofs_] = x
return dofs_, true
end
function action2(node_id, dofs)
""" If no coefficients on matrix D we can set essential boundary condition
only on master side and impose bc weakly on slave side, i.e., remove SPC
"""
dofs_ = intersect(dofs, all_dofs)
length(dofs_) == 1 || return dofs_, false
any(has_lagrange_coefficients(dofs_)) && return dofs_, false
if is_spc(C2, dofs_) && !is_spc(C2_, dofs_)
C1[dofs_,:] = C2[dofs_,:] = g[dofs_,:] = 0
return dofs_, true
elseif is_spc(C2_, dofs_) && !is_spc(C2, dofs_)
C1_[dofs_,:] = C2_[dofs_,:] = g_[dofs_,:] = 0
return dofs_, true
else
return dofs_, false
end
end
function action3(node_id, dofs)
""" Another option is to obey single point constraints
"""
dofs_ = intersect(dofs, all_dofs)
any(has_lagrange_coefficients(dofs_)) && return dofs_, false
if !is_spc(C2, dofs_) && is_spc(C2_, dofs_)
C1[dofs_,:] = C2[dofs_,:] = g[dofs_,:] = 0
return dofs_, true
elseif !is_spc(C2_, dofs_) && is_spc(C2, dofs_)
C1_[dofs_,:] = C2_[dofs_,:] = g_[dofs_,:] = 0
return dofs_, true
else
return dofs_, false
end
end
function action4(node_id, dofs)
""" If symmetry line, one possibility is to apply both conditions and
eliminate lagrange multiplier. """
dofs_ = intersect(dofs, all_dofs)
length(dofs_) != 1 && return dofs_, false
related_dofs = get_related_dofs(dofs_)
for j in related_dofs
has_anything(j) && continue
# copy one constaint to this dof
C1[j,:] = C1[dofs_,:]
C2[j,:] = C2[dofs_,:]
D[j,:] = D[dofs_,:]
g[j,:] = g[dofs_,:]
# make room for new constraint
C1[dofs_,:] = 0
C2[dofs_,:] = 0
D[dofs_,:] = 0
g[dofs_,:] = 0
dofs_ = [dofs_; j]
break
end
for j in related_dofs
has_anything(j) && continue
# set lagrange multiplier to 1
D[j,dofs_[1]] = 1.0
C1[j,dofs_[1]] = 1.0
dofs_ = [dofs_; j]
break
end
return dofs_, true
end
actions = [action1, action2, action3, action4]
function show_lambda_coefficients(dofs, C1)
for dof in dofs
status = dof in all_dofs ? " <-- overconstrained dof" : ""
r = C1[:, dof]
r[abs(r) .< 1.0e-9] = 0
length(nonzeros(r)) != 0 || continue
info("dof $dof: "*pretty_print_C1_row(r))
end
end
function show_rows_in_constraint_matrix(dofs, C2, D; show_status=true)
for dof in dofs
status = (dof in all_dofs) && show_status ? " <-- overconstrained dof" : ""
a = C2[dof,:]
b = D[dof,:]
a[abs(a) .< 1.0e-12] = 0
b[abs(b) .< 1.0e-12] = 0
if (length(nonzeros(a)) == 0) && (length(nonzeros(b)) == 0)
continue
end
info("dof $dof: "*pretty_print_constraint_equation(a, b, g[dof])*status)
end
end
function show_related_equations(dofs, C2, C2_, D, D_)
related_dofs = Set{Int64}()
G = [C2 D]
G_ = [C2_ D_]
for dof in dofs
dof in all_dofs || continue
c = find(G[dof,:])
length(c) == 0 && continue
push!(related_dofs, c...)
c = find(G_[dof,:])
length(c) == 0 && continue
push!(related_dofs, c...)
end
related_dofs = setdiff(related_dofs, all_dofs)
length(related_dofs) != 0 || return
info("----- Related equations -----")
show_rows_in_constraint_matrix(related_dofs, C2, D)
show_rows_in_constraint_matrix(related_dofs, C2_, D_)
end
function print_summary(node_id, dofs)
s = join(dofs, ", ")
info()
info("SUMMARY for node id $node_id with dofs $s:")
info("----- Current constraint -----")
info("lambda coefficients in C1 matrix are:")
show_lambda_coefficients(dofs, C1_)
info("rows in constraint matrix C2 & D")
show_rows_in_constraint_matrix(dofs, C2_, D_)
info("----- New constraint -----")
info("lambda coefficients in C1 matrix are:")
show_lambda_coefficients(dofs, C1)
info("rows in constraint matrix C2 & D")
show_rows_in_constraint_matrix(dofs, C2, D)
show_related_equations(dofs, C2, C2_, D, D_)
end
info("System is overconstrained by $(length(all_dofs)) dofs.")
info("Overconstrained_nodes: $(join(nodes, ", ")).")
info("Following dofs already constrained: $(join(all_dofs, ", ")).")
for node_id in nodes
dofs = [2*(node_id-1)+1, 2*(node_id-1)+2]
show_info && print_summary(node_id, dofs)
# try to resolve issue automatically
resolved = false
for (i, action) in enumerate(actions)
dofs, resolved = action(node_id, dofs)
info("algorithm $i solved issue? $resolved")
if resolved
break
end
end
if resolved
info("fixed: new setting is")
show_info && show_rows_in_constraint_matrix(dofs, C2, D; show_status=false)
show_info && show_rows_in_constraint_matrix(dofs, C2_, D_; show_status=false)
show_info && show_related_equations(dofs, C2, C2_, D, D_)
show_info && info()
continue
end
info("unable to resolve overconstrained situation, not continuing")
show_rows_in_constraint_matrix(dofs, C2, D; show_status=false)
show_rows_in_constraint_matrix(dofs, C2_, D_; show_status=false)
show_related_equations(dofs, C2, C2_, D, D_)
throw("failed to resolve overconstraint situation")
end
end