• id: JME-08-N03
• title: Types of Strain — Longitudinal, Shear, Volumetric
• tags: strain, longitudinal, shear, volumetric

Strain is the ratio of change in dimension to original dimension — it is dimensionless (no units). Longitudinal strain $= \Delta L / L$ (change in length per original length). Shear strain $= \Delta x / L = \tan\theta \approx \theta$ for small deformations, where $\theta$ is the angle of shear in radians. Volumetric strain $= \Delta V / V$ (fractional change in volume). Because strain is a ratio, it has no dimensional formula: [M$^0$ L$^0$ T$^0$].