Mechanical Considerations

Abstract

In a mechanical continuum two distinct types of forces act, body forces f and contact forces t. The body forces arise as a result of some distant action. They are long-range forces. The contact forces arise as a result of the contact of adjacent elements of a body. Macroscopically speaking, they are surface forces. Microscopically, they are caused by very short-range near-neighbor interactions between adjacent microscopic elements. The body force exerted by electric or magnetic fields will be neglected below. We will also neglect body-couples and surface-couples as well. The quantities being neglected can be shown to be very small in the linear theory with which we will be concerned.