Elasticity testing is looking at the area where a material or part will return to its initial state ones the load have been removed. This is the area before plastic or permanent deformation occurs.

### Simple Elasticity Testing Example

If you for example have 3 rod’s made of different materials and clamps each of them in one end. If you then apply a fixed load to the other end, you can measure a different deflection for each rod. The amount of deflection describe the elasticity of the material, and if all the specimens of materials are in exactly the same dimension, and clamped the exact same way, the elasticity of the materials can be compared to each other.

### Perform Elasticity Testing

When an elasticity test is done, the product of the test is a curve illustrating the load vs. the elongation of the sample. This can then be converted to a stress-strain curve by dividing the load with the cross-section of the part.

The stress and strain will initially increase with a linear correlation, which is the elastic area. The ratio between stress and strain is described by Hooke’s Law, and the slope of the line is defined by Yung’s modulus which also is known as modulus of elasticity.

### Yield Point

At some point the stress-strain curve will deviate from its initial linear shape, which is where plastic deformation starts. This point is called yield point and is the limit you would need to stay below to avoid permanent damage to a given product or part.

If you would like to know more about elasticity testing and how to use it as part of problem solving or risk mitigation, then our 8D Training or FMEA Training might be of interest to you.

Alternatively you can continue to our quality training page to see our available courses.

Go to Quality Training