Final answer:
Shear strain is falsely defined as the tangent of the angle of distortion; it is actually the ratio of the displacement caused by shear stress to the original transverse distance between surfaces.
Step-by-step explanation:
The statement that shear strain is defined as the tangent of the angle of distortion is false. Shear strain is actually defined as the ratio of the displacement of one surface relative to the other (Ax) to the original transverse distance (Lo) between the surfaces. In equations pertaining to shear deformation, this relationship is expressed as Ax/Lo, and it describes how far the layers shift in response to a shear stress without any change in the transverse length Lo.
Shear stress, on the other hand, is caused by forces (F) acting parallel to the surface, and it is defined as the magnitude of this force per surface area (A) where the shearing force is applied. The shear modulus (S) is used as a measure of how a material resists shear stress and is defined as the ratio of shear stress to shear strain.