Considering geometric simplifications on the general case of solid bodies, the discipline of

strength of materials studies one-dimensional linear elastic models. Generally, it studies the internal

forces and deformation of such one-dimensional structural elements as bars, beams, and shafts. To

this purpose, it is assumed that any applied load deforms the body only, without any rigid body

motion. In this context, many expressions are determined to calculate the stresses and strains in

structures which are composed of these basic structural elements. Therefore, a one-dimensional

description of general solid mechanics concepts is considered.