Deformation

Definition

Deformation is the change in shape or size of an object due to applied forces. It can be elastic (reversible) or plastic (permanent).

5 Must Know Facts For Your Next Test

1. Elastic deformation follows Hooke's Law, where stress is proportional to strain.
2. Plastic deformation occurs when the material is stressed beyond its yield strength.
3. The unit of measure for stress is Pascals (Pa), and for strain, it is dimensionless.
4. Young's modulus quantifies the stiffness of a material and relates stress and strain in elastic deformation.
5. Shear deformation involves changes in shape without a change in volume.

Review Questions

• What distinguishes elastic deformation from plastic deformation?
• How does Young's modulus relate to stress and strain?
• What are the units used to measure stress and strain?

Related terms

Stress: The force per unit area within materials that arises from externally applied forces.

Strain: The amount of deformation experienced by the body in the direction of the applied force divided by the initial dimensions of the body.

$$\text{Young's Modulus}$$: $$\text{A measure of the stiffness of a solid material, defined as stress over strain.}$$