Shear stress

Definition

Shear stress is a type of stress that occurs when forces are applied parallel or tangential to a material's surface, causing layers within the material to slide past each other. It is calculated as the force applied divided by the area over which it acts.

5 Must Know Facts For Your Next Test

1. Shear stress is given by the formula $\tau = \frac{F}{A}$, where $\tau$ is shear stress, $F$ is the force applied, and $A$ is the area.
2. In materials science, shear stress can lead to deformation or failure if it exceeds the material's shear strength.
3. Shear modulus (or modulus of rigidity) relates shear stress to shear strain and is denoted by $G$.
4. In fluids, shear stress plays a crucial role in understanding viscosity and fluid flow between layers.
5. Units of shear stress are typically Pascals (Pa) in the International System of Units (SI).

Review Questions

• What formula is used to calculate shear stress?
• How does shear stress differ from normal stress?
• What physical property relates shear stress to shear strain?

Related terms

Stress:

The internal resistance offered by a material when an external force is applied, measured as force per unit area.

Strain:

The deformation experienced by a material in response to an applied stress, measured as the change in dimension divided by original dimension.

Elastic Modulus:

A measure of a material's stiffness or rigidity, defined as the ratio of stress to strain within the elastic limit.