• id: JME-08-N02
• title: Types of Stress — Tensile, Compressive, Shear, Volumetric
• tags: stress, tensile, compressive, shear, hydraulic

Stress is the internal restoring force per unit area ($\sigma = F/A$, SI unit: Pa). Tensile stress stretches the body along the force direction. Compressive stress shortens it. Shear stress ($\tau = F/A$) acts tangentially, deforming the shape without changing volume. Volumetric (hydraulic) stress is uniform pressure applied from all directions — it equals the change in pressure $\Delta P$ and changes volume without changing shape. The dimensional formula of all types of stress is [M L$^{-1}$ T$^{-2}$], same as pressure.