Refactoring of beam shear calculation, add test for beam shea

StructureHelperTests/UnitTests/BeamShearTests/SectionEffectivenessFactorySP2018Tests.cs

@@ -0,0 +1,40 @@
+using NUnit.Framework;
+using StructureHelperCommon.Infrastructures.Exceptions;
+using StructureHelperLogics.Models.BeamShears;
+
+namespace StructureHelperTests.UnitTests.BeamShearTests
+{
+    [TestFixture]
+    public class SectionEffectivenessFactorySP2018Tests
+    {
+        private SectionEffectivenessFactorySP2018 factory;
+
+        [SetUp]
+        public void SetUp()
+        {
+            factory = new SectionEffectivenessFactorySP2018();
+        }
+
+        [Test]
+        public void GetShearEffectiveness_WhenRectangle_ReturnsExpectedValues()
+        {
+            // Act
+            var result = factory.GetShearEffectiveness(BeamShearSectionType.Rectangle);
+
+            // Assert
+            Assert.That(result.BaseShapeFactor, Is.EqualTo(1.5));
+            Assert.That(result.ShapeFactor, Is.EqualTo(1.0));
+            Assert.That(result.MaxCrackLengthRatio, Is.EqualTo(3.0));
+            Assert.That(result.MinCrackLengthRatio, Is.EqualTo(0.6));
+        }
+
+        [Test]
+        public void GetShearEffectiveness_WhenUnsupportedType_Throws()
+        {
+            // Act & Assert
+            Assert.Throws<StructureHelperException>(() =>
+                factory.GetShearEffectiveness((BeamShearSectionType)999));
+        }
+    }
+}
+