Stress, denoted by σ, is the external restoring force that acts on per unit area. It is expressed as N/m². It is used to calculate the stress applied to any given body when the force and area on which it is exerted are given in a problem. As a result, σ = F/A
σ is the amount of stress applied to the object
F denotes the force acting on the object.
The cross-sectional area is denoted by A.
Stress can also be defined as the force applied to an object that causes it to deform completely. We discovered how the stress formula is derived in physics terminology. Larger objects are known to be more resistant to a wide range of forces. We can use the same yield stress for the same material no matter how large the object is by using stress instead of force. Furthermore, stress and strain are inextricably linked, and as one rises, the other rises with it. And, the greater the object’s stress, the more deformation it experiences.
Normal stress occurs when an object is loaded by an axial force. When the axial force is divided by the cross-sectional area, normal stress is represented. It will happen when an object is compressed.
Longitudinal stress occurs when the length of the body changes due to the application of normal stress. Longitudinal stress is represented by dividing the deforming force by the cross-section area.
It is a type of stress in which the body volume changes as a result of the stress. Normal stress on an object causes it to change in length or volume, whereas tangential stress causes a change in the shape of the body, which is known as volume.
Tensile stress is defined as the force per unit area and the stress that occurs when a force is applied and increases the length of the body as a result of the force. It is observed when a rod is stretched in accordance with the third law of motion. Rubber is a common example of tensile stress, and stretching is the quantity associated with it.
When we apply a tangential force to a body, the shape and volume of the object change. The length of the object is reduced as a result of compression stress. It is the inverse of tensile stress.
Before discussing stress, a few concepts must be addressed. Furthermore, stress is defined as the amount of force (strength or energy) applied to an object divided by its cross-section area. Larger objects can also withstand greater forces. Furthermore, by employing stress rather than force, we can use the same yield stress for the same material regardless of the size of the object. Most importantly, stress and strain are inextricably linked, and as one rises, so does the other. Furthermore, as an object is subjected to more stress, it deforms until it fails.
The Stress dimensional formula is given by, [M1 L-1 T-2]
Where,
Stress = Force [Area]-1..,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, (1)
The area dimensional formula= [M0 L2 T0] . . . . (2)
Since Force= M × a = [M] × [M0 L1 T-2]
The force dimensional formula = [M1 L1 T-2] . . . . (3)
When we substitute equations (2) and (3) into equation (1), we get
Stress = [Area]-1 Force Alternatively, Stress = [M1 L1 T-2] × [M0 L2 T0]-1 = [M1 L-1 T-2]
As a result, stress is represented dimensionally as [M1 L-1 T-2].
The force acting across a small boundary per unit area of that boundary is defined as stress. As we all know, the force acting per unit area is referred to as pressure. Because stress and pressure are the same things. As a result, the SI unit of stress is Pascal. It has the same dimensional formula as pressure, which is M¹L⁻¹T⁻².
The dimensions of stress and pressure are the same, but the pressure is not the same as stress.
