CrackWidthCalculator has been added

StructureHelperCommon/Infrastructures/Enums/SectionStressStates.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StructureHelperCommon.Infrastructures.Enums
+{
+    public enum SectionStressStates
+    {
+        Tension,
+        Compressed,
+        Combined
+    }
+}

StructureHelperCommon/Infrastructures/Exceptions/ErrorString.cs

@@ -21,5 +21,6 @@
         public static string ResultIsNotValid => "#0016: Result is not valid";
         public static string ErrorOfExuting => "#0017: Error of executing";
         public static string ExpectedWas(System.Type expected, System.Type was) => $"{DataIsInCorrect}: Expected {expected}, but was {was}";
+        public static string ExpectedWas(System.Type expected, object obj) => ExpectedWas(expected, obj.GetType());
     }
 }