EXPERIMENTAL INVESTIGATION ON ELASTO-PLASTIC DEFORMATION OF IS:2062 GRADE C STEEL IN THE POST YIELD REGION

Rapid growth and tough competition in material processing industries such as automobile and aerospace demands precise components to be processed in short time. The processing steps involved in fabrication of intricate shaped final product involves various intermediate steps such as design, selection of material and manufacturing process etc. In these steps, a thorough understanding of material plastic behavior plays a vital role. Currently there is no acceptable model is available for a range of applications that gives solution to practical and theoretical issues. Most of the theories are either related to material or can be applied only to specific processes. These theories overgeneralized the physical real world situation using assumptions and empirical relations. Deformation involves changes the shape and size. Composites and other material exhibits some sort of inelasticity even under very low stresses. Constitutive relation can't treat the elastic and plastic deformations separately. Classical yield criteria fail to correlate the elastic plastic behavior for material deformation in 3-D. In the present investigation new generalized relation has been developed by employing the concept of activation energy to represent the material behaviour from elastic range to failure. This relation involves eight material parameters which includes two classical material constants like bulk modulus and shear modulus, two material viscosity terms and four in the form rule which relates elastic strain rate to plastic strain rate. All these material parameters can be obtained by conducting simple experiments. Experiments are carried out to find material parameter values. In the present work, experiments on the commercial grade mild steel and aluminum are discussed.