مشخصات پژوهش

Tensile stress-strain curve is of high importance in mechanics of materials particularly in numerical simulations of material deformations. The curve is usually obtained by experiment, but is limited by the necking phenomenon. Engineering stress-strain curve is converted to true stress-strain curve through simple formulas. The conversion, however, is correct up the point of necking. From this point on, the curve should be corrected taking account of stress triaxiality. Over the past several decades, a number of methods such as Bridgeman correction technique have been proposed. In this investigation a new technique based on strain energy in introduced. Strain energy is assumed to be equal to the external work in tensile test. The energy method is compared with different approaches such as Bridgeman-Leroy, Bridgeman, Davidenkov, Siebel and optimization aided numerical simulation. The results indicate that the energy method prediction is very close to numerical simulation, but at the same time it does not differ too significantly from the other approaches studied in this investigation