What is Elastic Limit?
Nov 18, 2022, 16:45 IST
An elastic limit is a stress that a material can withstand before permanent deformation. It is the upper limit of the material before plastic deformation of the material can occur. Once the stress or force is removed, then the material returns to its original figure. Elastomers like rubber have the maximum elastic limit. Hooke's law can explain this behavior.
| Table of Content |
Elastic Limit Testing
An elastic limit can be determined by measuring the most significant stress applied to a given specimen without any permanent deformation occurs. The stress-strain curve is a straight line for metals or other rigid materials because the elastic limit is equal to the proportional limit. Materials such as rubber and plastic are called apparent elastic limit because their stress-strain curve is not significantly straight.
What is the Proportional Limit?
The proportional limit is known as the highest stress at which both the stress and the strain is directly proportional so that the stress-strain graph is in a straight line. Therefore the gradient is equal to the modulus of the elasticity of the material. The proportional limit is always equal to the elastic limit for many metals.
Difference between Elastic Limit and Proportional Limit
| Elastic limit | Proportional limit |
| It is defined as the point at which the material generally remains elastic. | It is defined as the point at which both stress and the strain are directly proportional. |
Difference between Elastic Limit and Yield Point
Elastic limit and yield point are generlly almost same. But they do have a few differences as follows-
| Elastic limit | Yield point |
| Maximum stress the material can withstand before permanent deformation. | It is the amount of a stress that is present in the material before the permanent deformation. |
Real life Examples
- Rubber is one of the most pliable materials.
- Glass is more elastic than steel and also the other materials.
- A nail bends permanently when it is subjected to the shear stress of a hammer strike, indicating that it has hit its elastic limit.
- Quartz and copper, as well as Phosphorus, are almost plastic bodies.
- The bodies of paraffin wax and dirt are regarded to be entirely plastic.
Frequently Asked Questions (FAQs)
Q1. Define Elastic limit.
Ans. An elastic limit is the maximum stress while the material can withstand before permanent deformation.
Q2. Which type of elastomers has the highest elastic limit?
Ans. The highest elastic limit is elastomers like rubber.
Q3. What is the proportional limit?
Ans. A proportional limit is a point to which both stress and the strain are directly proportional.
Q4. What is the yield point?
Ans. It is defined as the amount of a stress present in the material before permanent deformation.
Q5. Which material has more elastic limit?
Ans. Steel is the most elastic material.
