Force combination was added

StructureHelperCommon/Models/Forces/ForceCombinationList.cs

@@ -0,0 +1,27 @@
+using StructureHelperCommon.Infrastructures.Enums;
+using StructureHelperCommon.Models.Shapes;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StructureHelperCommon.Models.Forces
+{
+    public class ForceCombinationList : IForceCombinationList
+    {
+
+        public string Name { get; set; }
+        public Point2D ForcePoint { get; private set; }
+        public List<IDesignForceTuple> DesignForces { get; private set; }
+
+        public ForceCombinationList()
+        {
+            DesignForces = new List<IDesignForceTuple>();
+            DesignForces.Add(new DesignForceTuple(LimitStates.ULS, CalcTerms.ShortTerm));
+            DesignForces.Add(new DesignForceTuple(LimitStates.ULS, CalcTerms.LongTerm));
+            DesignForces.Add(new DesignForceTuple(LimitStates.SLS, CalcTerms.ShortTerm));
+            DesignForces.Add(new DesignForceTuple(LimitStates.SLS, CalcTerms.LongTerm));
+        }
+    }
+}