ABSTRACT
Analysis of structural elements requires knowledge of the mechanics of materials. These principles permit a determination of stress and strain within a material subject to loading. These loads, or forces, acting on a body may be internal or external. The forces that resist separation or movement within the body are considered internal, while external forces are those transmitted by the body. Generally, the force acting on a body is proportional to the stress times the cross-sectional area:
F A= s (9.1)
Stress σ can also be referred to as the intensity of forces distributed over the cross section. Stresses imparted on a body induce deformations, which can change the shape, length, and cross-section of a body. In the design of engineering materials, it is important to avoid large deformations that affect the serviceability of a structure or machine. For the human body, pain and injury can result from excessive deformation under loading.
