Fix beam shear force calculator

StructureHelperLogics/Models/BeamShears/Logics/IBeamShearStrenghLogic.cs

@@ -0,0 +1,21 @@
+using StructureHelperCommon.Infrastructures.Interfaces;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StructureHelperLogics.Models.BeamShears.Logics
+{
+    /// <summary>
+    /// Implement logic for calculation of bearing capacity of inclined section for shear
+    /// </summary>
+    public interface IBeamShearStrenghLogic : ILogic
+    {
+        /// <summary>
+        /// Returns Bearing capacity of inclined section for shear
+        /// </summary>
+        /// <returns>Bearing capacity of inclined section for shear, N</returns>
+        double GetShearStrength();
+    }
+}