Types of stresses

1. Types Of Stresses Prepared by: Somesh Patani (131130119052) Jigar Munjani ( 131130119037)

2. S tress When a material is subjected to an external force, a resisting force is set up within the component, this internal resistance force per unit area is called stress. SI unit is N/m²(Pa). 1kPa=1000Pa, 1MPa=10^6 Pa, 1 Gpa =10^9Pa, 1 Terra Pascal=10^12 Pa In engineering applications, we use the the original cross section area of the specimen and it is known as conventional stress or Engineering stress

3. Direct Stress Direct stress may be normal stress or shear stress Normal stress ( σ ) is the stress which acts in direction perpendicular to the area. Normal stress is further classified into tensile stress Tensile stress is the stress induced in a body, when it is subjected to two equal and opposite pulls (tensile forces) as a result of which there is a tendency in increase in length It acts normal to the area and pulls on the area

4. Tensile stress ( σ )= Resisting force/ Cross sectional area= Applied force/Cross sectional area=P/A

5. Compressive stress Compressive stress =Resisting force/ cross sectional area= Applied force/ cross sectional area

6. Shear Stress Shear stress :- Stress Induced in a body, when subjected to two equal and opposite forces which are acting tangentially across the resisting section as a result of which the body tends to shear off across that section

7. Bending Shear stress When a member is being loaded similar to that in figure one bending stress (or flexure stress) will result.  Bending stress is a more specific type of normal stress.  When a beam experiences load like that shown in figure one the top fibers of the beam undergo a normal compressive stress.  The stress at the horizontal plane of the neutral is zero.  The bottom fibers of the beam undergo a normal tensile stress.  It can be concluded therefore that the value of the bending stress will vary linearly with distance from the neutral axis.

8. Torsional Shear stress When a machine member is subjected to the action of two equal and opposite couples acting in parallel planes (or torque or twisting moment), then the machine member is said to be subjected to Torsion The stress set up by torsion is known as torsional shear stress.