What is Stress and Strain Curve?

When you are talking about solids and various other materials, it is crucial to understand how these types of materials usually react when a force is applied. This process helps the students identify their strengths, deformations, and various other parameters acting on the objects, by calculating the various types of forces acting on them. And in order to find these parameters, the stress and strain quantities are important, and here in this article, we are going to provide a detailed guide about them below.

What is Stress?

Stress is defined as the force per unit area that is observed, in different types of materials, when an external force is applied. These external forces are generally uneven heating, permanent deformation, etc.

Types of Stress

There are different types of Stress that can be applied to a material, such as,

Compressive Stress

When a force acts on a body, it causes a reduction in the volume of the said body, resulting in deformation. This type of stress is referred to as Compressive stress.

Tensile Stress

When an external force is applied per unit area on a material, and it results in the stretching of the said material, then it is described as Tensile Stress.

What is Strain?

If a body experiences deformation due to the applied external force in a particular direction, then it is called strain. Moreover, the strain does not have any dimensions, as it only explains the change in the shape of the object.

Types of Strain

Similar to stress, strain is also differentiated into Compressive Strain and Tensile Strain.

Compressive Strain

Compressive strain is defined as the deformation observed on an object when compressive stress acts on it. And in this type of strain, the length of the material or object generally decreases.

Tensile Strain

The Tensile stress acting on a body or a material that causes the increase in the length of said material is referred to as a tensile strain.

Stress-Strain Curve

This graph explains how stress and strain act on a body with respect to each other, as well as the different regions formed on the graph.

• The OA line represents the Proportional Limit, as it described the region, where the material or body obeys Hooke’s Law. And this line can help students to calculate Young’s Modulus, using the ratio of

Stress and Strain Curve.

• Now, the AB line represents the Elastic Limit of the object, which means that after this point, the body does not retain its original shape or size, when the acting force is removed.
• As you can guess, the BC lines describe the Yield Point. Which, when force is applied on the material, then there is complete deformation in the object, which cannot be reversed, even if the force is removed.
• D point on the graph is the point beyond which students can observe the complete failure of the object, as it crosses the maximum stress a material can endure. This point is stated as Ultimate Stress Point.
• E is the Fracture of Breaking Point, at which students can observe the complete failure of deformation of the object, regardless of the force whether it is applied or removed.

Hooke’s Law

From the above sections, we have learned all about types of stress and strain, and their units, as well as a graphical representation of stress and strain on objects. Now let us talk about Hooke’s law of stress and strain, which plays an important role in helping us understand how stress and strain work on an object when force is applied.

According to this principle, the strain of the material is equal to the applied stress, in the elastic limit region of the said object or material. And it is represented as,

F = –k.x

F = Force

X = Extension of Length

K = Spring Constant

In the above article, we have explained in detail the terms, stress and Strain, how they act, units of stress and strain, types of stress and strain, etc. This will be helpful for students to solve any kind of problems from these chapters, or understand other subtopics easily from the next chapters. However, if you are still worried, about how to cover a large number of complex topics and chapters in Physics. Then the best solution for you is to join Online Coaching Platforms. Like the Tutoroot platform, which offers cost-effective online interactive classes that come with various amazing benefits for the students.