A Constitutive Stress?Strain Law for Metals with Sigmoidal Curves

A formulation is proposed for true stress–true strain relationships in the plastic regime that exhibit sigmoidal shapes, such as those of certain metastable austenitic stainless steels (MASS). It contains two terms, broadly accounting contributions to hardening from conventional plasticity and mechanical stimulation martensite formation. a continuous function, designed cover range zero up several tens percent. shown it suitable capture curve shapes this type—experimental data tensile testing MASS alloy over temperature, with good fidelity. The incorporates six independent parameters, although there may be scope limiting values they can have, facilitating convergence operations. Information presented about how obtained. equation thus expected use finite element method (FEM) models simulation deformation various scenarios, including indentation. Future work will involve exploration details this.