AnalysisViewModal and StrainTuple was added

Windows/ViewModels/Calculations/Calculators/SetPrestrainViewModel.cs

@@ -0,0 +1,42 @@
+using FieldVisualizer.ViewModels;
+using StructureHelperCommon.Models.Forces;
+using StructureHelperCommon.Services.Forces;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StructureHelper.Windows.ViewModels.Calculations.Calculators
+{
+    public class SetPrestrainViewModel : ViewModelBase
+    {
+        IStrainTuple SourceTuple;
+        private double coeffcient;
+
+        public double Coefficient
+        {
+            get
+            {
+                return coeffcient;
+            }
+            set
+            {
+                SetProperty(ref coeffcient, value);
+            }
+        }
+
+        public SetPrestrainViewModel(IStrainTuple sourceTuple)
+        {
+            SourceTuple = sourceTuple;
+            coeffcient = 1d;
+        }
+
+        public IStrainTuple GetStrainTuple()
+        {
+            var result = new StrainTuple();
+            StrainTupleService.CopyProperties(SourceTuple, result, coeffcient);
+            return result;
+        }
+    }
+}