Logics of accidental eccentricity were separated and tested

StructureHelperCommon/Models/Sections/Logics/IHasInputForce.cs

@@ -0,0 +1,17 @@
+using StructureHelperCommon.Models.Forces;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StructureHelperCommon.Models.Sections.Logics
+{
+    public interface IHasInputForce
+    {
+        /// <summary>
+        /// Initial tuple of force
+        /// </summary>
+        IForceTuple InputForceTuple { get; set; }
+    }
+}