Applications of modulus of elasticity
Knowledge of the modulus of elasticity of materials helps us to choose the correct material, in right dimensions for the right application. The following examples will throw light on this.
i) Most of us would have seen a crane used for lifting and moving heavy loads. The crane has a thick metallic rope. The maximum load that can be lifted by the rope must be specified. This maximum load under any circumstances should not exceed the elastic limit of the material of the rope. By knowing this elastic limit and the extension per unit length of the material, the area of cross section of the wire can be evaluated. From this the radius of the wire can be calculated.
ii) While designing a bridge, one has to keep in mind the following factors (1) traffic load (2) weight of bridge (3) force of winds. The bridge is so designed that it should neither bend too much nor break.
Three moduli of elasticity
Depending upon the type of strain in the body there are three different types of modulus of elasticity. They are
(i) Young's modulus
(ii) Bulk modulus
(iii) Rigidity modulus
The property of a material to regain its original state when the deforming force is removed is called elasticity. The bodies which possess this property are called elastic bodies. Bodies which do not exhibit the property of elasticity are called plastic. The study of mechanical properties helps us to select the material for specific purposes. For example, springs are made of steel because steel is highly elastic.