Stress vs. Strain in Materials Testing - Mechanical Engineering Interview Question

In materials testing, the terms stress and strain are commonly used to describe the behavior of materials under load:

• Stress: Stress is the force per unit area applied to a material. It is a measure of the internal resistance of a material to deformation under load.
• Strain: Strain is the measure of deformation or displacement of a material in response to stress. It is the change in length per unit length of the material.

The key difference between stress and strain is that stress is the applied force per unit area, while strain is the resulting deformation or change in shape of the material.

Understanding the relationship between stress and strain is crucial in materials testing as it helps engineers determine the mechanical properties of materials and their performance under different loading conditions.