# Simple shear In fluid mechanics, simple shear is a special case of deformation where only one component of velocity vectors has a non-zero value:  And the gradient of velocity is constant and perpendicular to the velocity itself: ,

where is the shear rate and: The displacement gradient tensor Γ for this deformation has only one nonzero term: Simple shear with the rate is the combination of pure shear strain with the rate of 1/2 and rotation with the rate of 1/2 : Important examples of simple shear include laminar flow through long channels of constant cross-section (Poiseuille flow), and elastomeric bearing pads in base isolation systems to allow critical buildings to survive earthquakes undamaged.

## Simple shear in solid mechanics

In solid mechanics, a simple shear deformation is defined as an isochoric plane deformation in which there are a set of line elements with a given reference orientation that do not change length and orientation during the deformation. This deformation is differentiated from a pure shear by virtue of the presence of a rigid rotation of the material.

If e1 is the fixed reference orientation in which line elements do not deform during the deformation and e1  e2 is the plane of deformation, then the deformation gradient in simple shear can be expressed as We can also write the deformation gradient as 