von Mises (Equivalent) stress calculation

A common way to express the multidirectional tensor stress components is to combine them into an equivalent stress magnitude. This equivalent stress is also known as the von Mises stress (σv). The following equation shows how the six tensors (σxx, σyz, and so on) are combined to produce the von Mises stress. This equation is applicable to isotropic materials loaded within their elastic range. An isotropic material has the same modulus of elasticity and Poisson's ratio for loads applied in any direction. Poisson's ratio is a measure of how much a material deforms laterally when stressed axially.