Tensile Strength Test on Mild Steel.pptx

This presentation tell us about the tensile strength test on mild steel

1. Introduction : Strength: Strength is the property of a material that represents its ability to resist internal forces or stress. Stress: Stress is defined as the intensity of internal force developed when an external force is applied on an engineering materials . In other words, it is defined as “Internal resistance per unit area” that is – stress , S = There are three types of stress – Tensile stress Compressive stress Shearing stress  

2. Strain: Strain is measure of deformation produced by the application of external force. In other words, it is defined as “deformation per unit length” that is – Here, = strain elongation L = original length   Proportional Limit : The proportional limit is the point on a material’s stress-strain curve up to which the material obeys Hooke’s Law , meaning stress is directly proportional to strain . In this linear region, the material deforms elastically , and the ratio of stress to strain remains constant, represented by the Young’s Modulus . At this stage: The material will fully recover its original shape when the load is removed. The stress-strain curve is a straight line from the origin to the proportional limit. This point marks the end of purely elastic and linear behavior . Beyond the proportional limit, the material still behaves elastically for a short range (up to the elastic limit ) but the relationship between stress and strain becomes nonlinear .

3. Elastic Limit: The maximum stress a material can withstand and still return to its original shape after unloading. Beyond this, permanent deformation occurs. Yield Point: The point where the material begins to deform plastically , showing a significant increase in strain without any increase (or even a slight drop) in stress . Ultimate Stress (Tensile Strength): The maximum stress the material can withstand before necking begins. This is the highest point on the stress-strain curve. Rupture Strength (Fracture Point): The stress at which the material breaks or fails. For structural steel, it is slightly lower than the ultimate stress .

4. Hooke's Law: Hooke's law specified merely that stress is proportional to strain . In other words, if any load is applied to an engineering material, then the strain occurs due to stress and is proportional to each other. S∝ ε⇒ S=E ε Here, S = Stress ε = Strain E = Modulus of Elasticity

5. Calculations:

6. Results: From the stress strain curve Results Yield stress 333.13 N/mm² Ultimate Strength 379.61 N/mm² Tensile Strength 1.139535 N/mm² Percent Elongation 17.1875 % Modulus of Elasticity 20979 Gpa

7. Practical Application: Material Selection – Ensures materials have suitable strength and ductility for engineering use. Quality Control – Verifies materials meet required standards in manufacturing. Safety Assurance – Prevents failure in critical components (e.g., cars, aircraft). Property Evaluation – Determines strength, stiffness, and ductility. Research & Development – Tests new materials in labs and industry.