Types of Stress

Stresses are classified as:-

Normal Stress :-  The stress which acts perpendicular to the area is known as Normal Stress.

It has two types:- 

1. Tensile Stress :- It induced in a body, when body is subjected to two equal and opposite pulls.

• It is caused due to tension in body.
• Due to tensile stress body length is increases but area of cross-section of body is decreases.

    2. Compressive Stress :- It induced in a body, when body is subjected to two equal and opposite

        pushes.

• It is caused due to Compression in body.
• Due  to compressive stress body length is decreases but  area of cross-section of body is increases.

NOTE :- Generally Tensile Stress is taken as Positive (+) and Compressive Stress is taken as

                 Negative(-ve).

Shear Stress :- The stress which caused due to tangential force is known as Shear Stress.

• It is denoted by Greek letter 𝝉 (tau).
• It is caused by two equal and opposite parallel forces not in co-linear.

Torsional Stress:- When a shaft is subjected two equal and opposite Torque then stress induced in a

                               shaft due to this torque is known as Torsional Stress.

• It is also known as Torsional Shear Stress.
• Torsional Stress is find by Torsional Equation.

                               Where, 𝝉  =  Torsional Stress or Torsional Shear Stress induced in shaft

                                            r  =  Radius of shaft

                                           T  =  Torque or Twisting Moment

                                           J   =  Moment of Inertia

                                          C   =  Modulus of Rigidity for Shaft Material

                                           𝜽  =  Angle of twist

                                            ᶩ   =  Length of shaft

Bending Stress :- When a member is subjected a load (Generally perpendicular to its axis), then

                               stress induced in that member due to this load is known as Bending Stress.

• Bending Stress is find by Bending Equation.

                                              Where, 𝞼 =  Bending Stress

                                                           y =  Distance from Neutral Axis

                                                          M =  Bending Moment

                                                           I  =  Second Moment of Area

                                                          E  =  Young's Modulus of Elasticity

                                                          R  =  Radius of curvature

Combined Stress :- When two or more stress act simultaneously on a body or member then

                                  collectively all stress is known as Combined Stress.