Abstract
We study an arbitrary deformation of a configuration of a body and show that this deformation may be reduced to a sequence of two special deformations: the rotation and stretching. The kinematics of a deformation is also considered. We introduce a notion of a vorticity vector and discuss its relationship with the antisymmetric part of the velocity gradient.
Keywords: Deformation, Deformation gradient, Deformation rate tensor, Kinematics of a deformation, Polar decomposition theorem, Rotation tensor, Stretching tensor, Velocity gradient, Vorticity vector.