Author: admin

Poisson, Cauchy, and George G. Stokes showed that the equations of the general theory of elasticity predicted the existence of two types of elastic deformation waves which could propagate through isotropic elastic solids. These are called body waves. In the faster type, called longitudinal, dilational, or irrotational waves, the particle motion is in the same direction as that of wave…

Linear elasticity as a general three-dimensional theory began to be developed in the early 1820s based on Cauchy’s work. Simultaneously, Navier had developed an elasticity theory based on a simple corpuscular, or particle, model of matter in which particles interacted with their neighbours by a central force attraction between particle pairs. As was gradually realized, following work…

The 1700s and early 1800s were a productive period during which the mechanics of simple elastic structural elements were developed—well before the beginnings in the 1820s of the general three-dimensional theory. The development of beam theory by Euler, who generally modeled beams as elastic lines that resist bending, as well as by several members of the Bernoulli family and…

The English scientist Robert Hooke discovered in 1660, but published only in 1678, that for many materials the displacement under a load was proportional to force, thus establishing the notion of (linear) elasticity but not yet in a way that was expressible in terms of stress and strain. Edme Mariotte in France published similar discoveries in 1680 and, in addition, reached an…

Solid mechanics developed in the outpouring of mathematical and physical studies following the great achievement of Newton in stating the laws of motion, although it has earlier roots. The need to understand and control the fracture of solids seems to have been a first motivation. Leonardo da Vinci sketched in his notebooks a possible test of the tensile strength of a wire. Galileo,…

Mechanics of solids, science concerned with the stressing, deformation, and failure of solid materials and structures. What, then, is a solid? Any material, fluid or solid, can support normal forces. These are forces directed perpendicular, or normal, to a material plane across which they act. The force per unit of area of that plane is called the normal stress. Water at the base of a pond,…