Usage of true stress-strain curve for FE simulation and the influencing parameters

Abstract

Computer simulations require appropriate input data to match the relevant calculated results with those of experiments. The true stress-strain curve suitable for finite element analysis is describing the non-linear behaviour of the steel material with a proper pre-peak as well as necking stress-strain relationship. The pre-peak part of true stress-strain curve can be easily covered by an analytical method (i.e. logarithmic equations), but the necking part of the curve cannot be described by such a relationship between the normalized and the true stress-strain curves. Simple tensile test of steel specimen was performed to establish the true stress-strain curve in ANSYS software. Different sizes of finite elements were applied for the non-linear FE analysis to find an appropriate size function while creating the necking part of true stress-strain curve using an iterative method. Stress and strain from the computer analyses were compared with the results of the tensile test. The dependence of size of finite elements and/or element type was analysed to achieve the most precise results.