A complemented multiaxial creep constitutive model for materials with different properties in tension and compression

Abstract

A complemented multiaxial creep constitutive model is proposed in this paper. The model is able to describe the different creep behaviors in tension and compression under a complex multiaxial stress state. To improve the convergence and adaptability for large-scale structures in engineering, a complemented constitutive model is established by complementing the shear part of the creep constitutive matrixes in principal space through a limitation process. The finite element method and forward Euler method are used to establish the numerical calculation framework. Efficient solution procedures are also proposed and implemented. Room temperature creep experiments of titanium alloy Ti–6Al–3Nb–2Zr–1Mo are performed. It is found that titanium alloy has different creep properties in tension and compression. The numerical results show that the proposed creep constitutive model and numerical calculation framework are in good agreement with the experimental results. The response of each specific creep strain component under a complex stress multiaxial state can be accurately calculated, and the different properties of the creep response in tension and compression in different directions are reflected.