Crack Calculator was added

StructureHelperLogics/NdmCalculations/Cracking/ExponentialSofteningLogic.cs

@@ -0,0 +1,59 @@
+using StructureHelperCommon.Infrastructures.Exceptions;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StructureHelperLogics.NdmCalculations.Cracking
+{
+    public class ExponentialSofteningLogic : ICrackSofteningLogic
+    {
+        private double forceRatio;
+        private double powerFactor;
+
+        public double PowerFactor
+        {
+            get => powerFactor;
+            set
+            {
+                if (value < 0)
+                {
+                    throw new StructureHelperException(ErrorStrings.DataIsInCorrect + ": Power Factor must not be less than zero");
+                }
+                powerFactor = value;
+            }
+        }
+        public double BettaFactor { get; set; }
+        public double ForceRatio
+        {
+            get => forceRatio;
+            set
+            {
+                if (value < 0)
+                {
+                    throw new StructureHelperException(ErrorStrings.DataIsInCorrect + ": Force Ratio must not be less than zero");
+                }
+                else if (value > 1)
+                {
+                    throw new StructureHelperException(ErrorStrings.DataIsInCorrect + ": Force Ratio must not be greater than 1.0");
+                }
+                forceRatio = value;
+            }
+        }
+        public double FiMin {get;set;}
+        public ExponentialSofteningLogic()
+        {
+            FiMin = 0.2d;
+            PowerFactor = 2d;
+            BettaFactor = 0.8;
+        }
+        public double SofteningFactor()
+        {
+            double fi;
+            fi = 1 - BettaFactor * Math.Pow(ForceRatio, PowerFactor);
+            fi = Math.Max(fi, FiMin);
+            return fi;
+        }
+    }
+}