update

Sources/TestingConsole/Program.cs

@@ -18,7 +18,8 @@ static void Main(string[] args)
 
             //TimoshenkoBeamChecker.Test2();
             //BriefFiniteElementNet.Validation.GithubIssues.Issue158.Run();
-            BriefFiniteElementNet.Validation.GithubIssues.Issue161.Run();
+            //BriefFiniteElementNet.Validation.GithubIssues.Issue161.Run();
+            BriefFiniteElementNet.Validation.GithubIssues.Issue174.Run();
             //EulerBernouly2nodeChecker.TestConsoleBeam();
 
             Console.Write("Done");

Validation/Validation/BriefFiniteElementNet.Validation.csproj

@@ -78,6 +78,7 @@
     <Compile Include="GithubIssues\Issue158.cs" />
     <Compile Include="GithubIssues\Issue159.cs" />
     <Compile Include="GithubIssues\Issue161.cs" />
+    <Compile Include="GithubIssues\Issue174.cs" />
     <Compile Include="GithubIssues\Issue23.cs" />
     <Compile Include="GithubIssues\Issue24.cs" />
     <Compile Include="GithubIssues\Issue25.cs" />

Validation/Validation/GithubIssues/Issue174.cs

@@ -0,0 +1,72 @@
+using BriefFiniteElementNet.Elements;
+using BriefFiniteElementNet.Loads;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace BriefFiniteElementNet.Validation.GithubIssues
+{
+    public static class Issue174
+    {
+        public static void Run()
+        {
+            var load = new PartialNonUniformLoad(); //creating new instance of load
+
+            var l = 6.5;
+
+            var model = new Model();
+
+            Node n1 = new Node(0, 0, 0) { Label = "n0" };
+            Node n2 = new Node(l, 0, 0) { Label = "n1" };
+
+            var bar = new BarElement(n1, n2) { Label = "e0" };
+
+            model.Nodes.Add(n1);
+            model.Nodes.Add(n2);
+            model.Elements.Add(bar);
+
+            var x1 = 2.0;
+            var x2 = 5.0;
+            var x3 = 6.5;
+
+            var xi1 = bar.LocalCoordsToIsoCoords(x1)[0];
+            var xi2 = bar.LocalCoordsToIsoCoords(x2)[0];
+
+            var p1 = 1.8 * 9806.65;//1.8 ton/m = 1.8 * 9806.65 N/m
+            var p2 = 2.3 * 9806.65;//2.3 ton/m = 1.8 * 9806.65 N/m
+
+            // For the case of a triangular load on a beam
+            load.SeverityFunction = BriefFiniteElementNet.Mathh.SingleVariablePolynomial.FromPoints(xi1, p1, xi2, p2);
+            load.StartLocation = new IsoPoint(xi1);      //set locations of trapezoidal load
+            load.EndLocation = new IsoPoint(xi2);
+
+            load.Direction = -Vector.K;
+            load.CoordinationSystem = CoordinationSystem.Global;
+
+            n1.Constraints = Constraints.MovementFixed;
+            n2.Constraints = Constraints.MovementFixed & Constraints.FixedRX;
+
+            var sec = new BriefFiniteElementNet.Sections.UniformGeometric1DSection(SectionGenerator.GetISetion(0.24, 0.67, 0.01, 0.006));
+            var mat = BriefFiniteElementNet.Materials.UniformIsotropicMaterial.CreateFromYoungPoisson(210e9, 0.3);
+
+            bar.Material = mat;
+            bar.Section = sec;
+
+            var u1 = load;
+
+            bar.Loads.Add(u1);
+
+            model.Solve_MPC();
+
+            var r1 = n1.GetSupportReaction();
+            var r2 = n2.GetSupportReaction();
+
+            Console.WriteLine("support reaction of n1: {0}", r1);
+            Console.WriteLine("support reaction of n2: {0}", r2);
+
+            //var frc = bar.GetGlobalEquivalentNodalLoads(u1);
+        }
+    }
+}

docs/example/UniformLoadCoordSystem/index.rst

@@ -132,7 +132,7 @@ Based on `toturial in www.learnaboutstructures.com <http://www.learnaboutstructu
 
 So in this example we do not need theta value itself, but we need `Cos(θ)` or more precise absolute value of it `|Cos(θ)|`. Due to elementary trigonometry relations `Cos(θ)=Sin(90°-θ)`. So instead of `|Cos(θ)|` we can calculate `|Sin(α)|` where `α = 90°-θ` and `α` equals to angle between load direction and element direction. For finding `|Sin(α)|` we can use length of cross product of two unit vectors of element direction and load direction. This coefficient is always a non negative value and less than or equal to `1.0`. If element is horizontal then `|Cos(θ)| = 1.0` if element is vertical then `|Cos(θ)| = 0.0`.
 
-.. hint:: Note that actually two vectors have to angles between them, a bigger one and a smaller one, but absolute value of cosine of them both are same i.e `|Cos(θ)| = |Cos(180°-θ)|`
+.. hint:: Note that actually two vectors have tow angles between them, a bigger one and a smaller one, but absolute value of cosine of them both are same i.e `|Cos(θ)| = |Cos(180°-θ)|`