Merge 3c82c7d into c337df5

src/FEMTruss.jl

@@ -34,13 +34,14 @@ function get_formulation_type(::Problem{Truss})
 end
 
 """
-   get_K_and_T(element::Element{Seg2}, nnodes, ndim, time)
-   This function assembles the local stiffness and transformation matrix
-   Need this to find element forces later on
+   get_Kg_and_Tg(element::Element{Seg2}, nnodes, ndim, time)
+   This function assembles the local stiffness uses global transformation matrix
+   to make the global version of the local stiffnes matrix
+   Need these to find element forces later
    Will need to change allocation strategy to pre-allocation later
    Can discuss if we really need nnodes, since that is always 2 for trusses
 """
-function get_K_and_T(element::Element{Seg2}, nnodes, ndim, time)
+function get_Kg_and_Tg(element::Element{Seg2}, nnodes, ndim, time)
     ndofs = nnodes*ndim
     K = zeros(ndofs,ndofs)
     T = zeros(2, ndofs*2)
@@ -96,7 +97,7 @@ function assemble!(assembly::Assembly, problem::Problem{Truss},
     #Require that the number of nodes = 2 ?
     nnodes = length(element)
     ndim = get_unknown_field_dimension(problem)
-    K,T = get_K_and_T(element, nnodes, ndim, time)
+    K,T = get_Kg_and_Tg(element, nnodes, ndim, time)
     gdofs = get_gdofs(problem, element)
     add!(assembly.K, gdofs, gdofs, K)
     #add!(assembly.f, gdofs, f)
@@ -132,6 +133,6 @@ function assemble_elements!(problem::Problem, assembly::Assembly,
     end
 end
 
-export Truss
+export Truss, get_Kg_and_Tg
 
 end

test/test_problems.jl

@@ -65,8 +65,20 @@ using FEMTruss
     @test isapprox(full(ls.u), u_glob)
 
     # support forces
-    #println("K = ", full(ls.K))
-    #println("f = ", full(ls.f))
-    #println("u = ", full(ls.u))
-    println("la = ", full(ls.la))
+    support_forces = full(ls.K*ls.u)[1:4]
+    # This is the same as ls.la negated
+    # println("la = ", full(ls.la))
+    # The support forces from Sofistik
+    Rf = [-6.78823, -3.39411, -2.26274, 1.13137]
+    @test isapprox(support_forces, Rf, rtol=1e-5)
+    #find local truss Forces
+    K1,T1 = get_Kg_and_Tg(el1, 2,2, 0.0)
+    f_loc1 = T1*K1*ls.u[[1,2,5,6]] # No local forces her to add_elements
+    # both element forces should be stretch, item1 is negative
+    @test isapprox(-f_loc1[1], f_loc1[2])
+    @test isapprox(f_loc1[2], 7.58947, rtol=1e-5)
+    K2,T2 = get_Kg_and_Tg(el2, 2,2, 0.0)
+    f_loc2 = T2*K2*ls.u[3:6]
+    @test isapprox(-f_loc2[1], f_loc2[2])
+    @test isapprox(f_loc2[2], 2.52982,rtol=1e-5)
 end