The role of a loading surface in viscoplasticity theory

• Published in: Acta mechanica Vol. 69; no. 1-4; pp. 77 - 96
• Main Authors: Yen, C. F., Eisenberg, M. A.
• Format: Journal Article
• Language: English
• Published: Wien Springer 01.12.1987; New York, NY
• Subjects: Exact sciences and technology; Fundamental areas of phenomenology (including applications); Inelasticity (thermoplasticity, viscoplasticity...); Physics; Solid mechanics; Structural and continuum mechanics; Viscoplasticity
• ISSN: 0001-5970; 1619-6937
• DOI: 10.1007/BF01175715

A multiaxial theory of viscoplasticity is further generalized to incorporate an isotropic loading surface and an anisotropic hardening rule for the unsymmetric cyclic distortion of the yield surface. The loading surface is defined as the smallest surface in stress space containing all the previous loading points; and the subsequent elastic region is assumed to be defined jointly by a yield surface and an isotropic surface which is contained by the loading surface and expands with a rate depending on the location of the loading point and the quasistatic loading point. The theory is applied to the modeling of stress--strain response and yield surface deformation of 1100 Al subject to non-proportional loading in tension--torsion space. 25 ref.--AA(UK).