Ebook: On the constitutive equations for cyclic plasticity under nonproportional loading

International Journal of Plasticity, Vol. 1, p. 317-330, 1985.
Office National d'Etudes et de Recherches Aerospatiales (ONERA).
Experimental results on 316 stainless steel, at room temperature, under strain controlled axial-torsion loadings, point out a large difference in strengthening between proportional and nonproportional loadings. The maximum difference is produced by 90 out of phase straining. In this paper we discuss the possibility of describing this additional hardening, without any new internal variable, by only modifying the expression for the yield criterion.