Comparison of constitutive relationships of tubular materials based on incremental theory and total strain theory

Abstract

Finite-element simulation was performed by feeding the parameters K and n values obtained from tube hydraulic bulge test into the finite element model to compare the constitutive relationships of tubular material determined by the methods based on the incremental theory and total strain theory. According to the mechanical model of tube hydraulic bulge, the constitutive relationships of tubular material were determined respectively via the incremental theory and the total strain by adopted the deformation data obtained from simulation. The K and n values obtained by the two methods were compared and compared with the input values of finite element, respectively. The influence of the error of finite element on the K and n values was analysed. The results show that K and n values obtained by the incremental theory are less than those obtained by the total strain theory, and the values obtained by the former are more closer to the input values of finite element.