Mechanical Properties of Materials

Abstract

The mechanical properties of materials, their strength, rigidity and ductility, are of vital importance in determining their fabrication and possible practical applications. Materials exhibit a wide range of mechanical properties ranging, for example, from the hardness of diamond to the ductility of pure copper and the amazing elastic behaviour of rubber. Furthermore many materials behave quite differently when stressed in different ways; for example cast iron, cement and masonry are much stronger in compression than in tension, a fact that was not lost on early architects who avoided using materials in tension whenever possible, whereas wood is several times stronger in tension than it is in compression because the cell walls in the wood structure tend to buckle in compression. In the subsequent sections of this chapter the various mechanical properties of materials are discussed and an attempt is made to explain the behaviour of materials under stress. Initially, however, a brief review is given of some of the experimental techniques that are used to investigate these mechanical properties.