 Critical resolved shear stress

The critical resolved shear stress is the shear stress on a specified slip system at which dislocation motion produces slip under stated conditions. For simple uniaxial loading, the resolved component is $\tau =\sigma \cos \varphi \cos \lambda$, with angles to the slip-plane normal and slip direction.

The threshold depends on material state, temperature, obstacles, and deformation history. A crystal can therefore begin to slip at different applied tensile stresses in different orientations even when the slip system has the same critical resolved threshold.

Critical resolved shear stress (CRSS) is a fundamental concept in materials science and engineering, particularly in the study of plastic deformation in crystalline materials. It refers to the minimum shear stress required to initiate and propagate slip, which is the process of deformation in which a material can change shape without an accompanying change in volume. In crystalline materials, the atomic structure is organized in a highly ordered lattice.