Stress-Strain Relationship-Breaking Force

This article will provide you with an in-depth understanding of Stress strain relationship and breaking force. This topic covers a huge part of your physics examination. In order to score more in your examination, this topic is a must for you. Read this article and get the best out of it. 

What is Stress?

Stress is the ratio between the internal resisting force, which is produced when the object is deformed over an area. Newton per square metre is the SI unit of stress. According to the CGS unit, stress is defined by dyne per centimetre inverse square. It’s important to learn the dimensional formula of stress, which is [ML-1T-2]. The formula of stress here is: 

Stress = Force/Area

Types of stress

There are two types of stress which are listed below:

Normal Stress

The restoring force per unit area, which is perpendicular to the body surface, is defined as normal stress.

Further, normal stress is divided into two parts which are given below:

• Tensile Stress
• Compressive Stress

Tangential Stress

Stress is known as tangential stress when the elastic restoring force or a deforming force acts parallel to the surface area.

What is Strain?

Strain can be defined by just a numerical value, as it is a dimensionless quantity. If you calculate the ratio of change in the size of an object to the original size of the object, this will help you calculate strain. 

Types of Strain

There are a total of three types of strain, which are as follows:

Longitudinal Strain

If the length of an object is affected due to a deforming force, then the strain which is produced in the body is termed a longitudinal strain. It is also called tensile strength. The formula of longitudinal strain is given below:

Longitudinal Strain = Change in the Length/Original Length

Volumetric Strain

If there’s a deforming force, which is producing a change in the volume of an object, then the strain produced is known as volumetric strain. 

Volumetric Strain = Change in Volume/Original Volume

Shear Strain

Due to tangential stress, if an angle is created within the object, then the strain is known as the shear strain. The formula for shear strain is as follows:

Shear strain = = Lh

where, 

L is the change in the length of the side.

h is the actual height of the object without deformation

Stress-Strain Relationship

The stress-strain relationship can be defined on the basis of Hooke’s law. Whenever there are small deformations, then stress will be directly proportional to strain. 

Hooke’s Law

Whenever there are small deformations, then the stress and strain are directly proportional to each other. This law is known as Hooke’s law. The formula of this law is given below:

Stress is directly proportional to strain

So, stress = k Strain

Where,

k is the proportionality constant and is also known as modulus of elasticity

What is Breaking Force?

If an object has a large area of cross-section and another object has a small area of cross-section, then the breaking force of both the objects will be different. This implies that the breaking force of an object depends upon the area of cross-section of a particular object. Breaking force is obtained by the multiplication of maximum stress that the body can withstand and the area of cross-section of the object for which you want to find out the breaking force. The formula for breaking force is provided below:

Breaking Force = Area of the cross-section of the object maximum Stress

Conclusion

After reading this article, you can differentiate between stress and strain. You will also have a deep understanding of what stress is, what strain is, and their variations. The formulas are the most important. 

There’s a relationship between stress and strain, which is also very important from an examination point of view. 

You will find the applications of stress and strain in many of your real-life problems 

For example:Stretching of rubber band by applying force is causing stress which leads to strain(change in the length of rubber band).