Suggestion of a New Definition of Angular Strain

A new definition of angular strain is put forward in this paper. Analogous to the definition of linear strain, angular strain is also defined as a rate of change(of angular displacement).It is verified that the new definition is equivalent to the original, but it is more convenient for geometrical interpretations. Using this new definition we deduce the transformation formulas for the rotation of coordinate axes, erect the strain tensor and verify the Hooke's law for shearing.