Added tests for dynamic relaxation time solver

Author: mdienst

test/time_solvers/test_dynamic_relaxation.jl

@@ -1,3 +1,46 @@
+@testitem "DynamicRelaxation wrong input" begin
+    @test_throws ArgumentError DynamicRelaxation(steps=0)
+    @test_throws ArgumentError DynamicRelaxation(steps=10, stepsize=0)
+    @test_throws ArgumentError DynamicRelaxation(steps=10, damping_factor=0)
+end
+
+@testitem "dynamic_relaxation_check" begin
+    dr = DynamicRelaxation(steps=1)
+    dr.n_steps = -1
+    msg = "`n_steps` of DynamicRelaxation smaller than zero!\n"
+    @test_throws ErrorException(msg) Peridynamics.dynamic_relaxation_check(dr)
+
+    dr = DynamicRelaxation(steps=1)
+    dr.Δt = -1
+    msg = "`Δt` of DynamicRelaxation smaller than zero!\n"
+    @test_throws ErrorException(msg) Peridynamics.dynamic_relaxation_check(dr)
+
+    dr = DynamicRelaxation(steps=1)
+    dr.Λ = -1
+    msg = "`Λ` of DynamicRelaxation smaller than zero!\n"
+    @test_throws ErrorException(msg) Peridynamics.dynamic_relaxation_check(dr)
+end
+
+@testitem "_init_density_matrix" begin
+    using Peridynamics
+    position = [0.0 1.0 0.0 0.0
+                0.0 0.0 0.0 1.0
+                0.0 0.0 1.0 0.0]
+    volume = fill(1.0, 4)
+    body = Body(BBMaterial(), position, volume)
+    material!(body; horizon=1.5, rho=8e-6, E=210e3)
+    point_set!(body, :a, 1:2)
+    material!(body, :a; horizon=1.5, rho=7.8e-6, E=200e3)
+
+    dr = DynamicRelaxation(steps=1)
+    dh = Peridynamics.threads_data_handler(body, dr, 1)
+    chunk = dh.chunks[1]
+    Peridynamics._init_density_matrix!(chunk,dr,chunk.paramsetup)
+
+    @test chunk.storage.density_matrix ≈  [4.0e6  4.0e6  4.2e6  4.2e6
+                                           4.0e6  4.0e6  4.2e6  4.2e6
+                                           4.0e6  4.0e6  4.2e6  4.2e6]
+end
 
 @testitem "show DynamicRelaxation" begin
     io = IOBuffer()