Chapter 3. Problems in Elasticity
As pointed out in Section 1.1, the approaches in widespread use for determining the influence of applied loads on elastic bodies are the mechanics of materials or elementary theory (also known as technical theory) and the theory of elasticity. Both must rely on the conditions of equilibrium and make use of a relationship between stress and strain that is usually considered to be associated with elastic materials. The essential difference between these methods lies in the extent to which the strain is described and in the types of simplifications employed.
The mechanics of materials approach uses an assumed deformation mode or strain distribution in the body as a whole and hence yields the average ...