A review of some plasticity and viscoplasticity constitutive theories

A dislocation-based model for all hardening stages in large strain deformation

Modelling of work hardening and stress saturation in FCC metals

Austenitic steels can exhibit both high strength and ductility due to a particularly high work hardening rate. Among all the possible deformation modes for austenitic steels, Twinning Induced Plasticity (TWIP) has the most beneficial effect on the work-hardening. It is believed that deformation twins increase the work-hardening rate by acting as obstacles for gliding dislocations. Many studies have investigated this point experimentally using microscopy. On a physical basis, the purpose of this study is to develop a work-hardening model taking into account the interaction between twinning and dislocation gliding. The results from the model are in good agreement with the tensile test results.

Modelling of TWIP effect on work-hardening

4 – the theory of subcritical crack growth with applications to minerals and rocks

J.L. Chaboche, Unified Cyclic Viscoplastic Constitutive Equations: Development, Capabilities, and Thermodynamic Framework. Y. Estrin, Dislocation-Density Related Constitutive Modeling. R.W. Evans and B. Wilshire, Constitutive Laws for High-Temperature Creep and Creep Fracture. G.A. Henshall, D.E. Helling, and A.K. Miller, Improvements in the MATMOD Equations for Modeling Solute Effects and Yield-Surface Distortions. A.S. Krausz and K. Krausz,The Constitutive Law of Deformation Kinetics. E. Krempl, A Small-Strain Viscoplasticity Theory Based on Overstress. J. Ning and E.C. Aifantis, Anisotropic and Inhomogenous Plastic Deformation of Polycrystalline Solids. S.V. Raj, I.S. Iskowitz, and A.D. Freed, Modeling the Role of Dislocation Substructure During Class M and Exponential Creep. K. Krausz and A.S. Krausz, Comments and Summary. Subject Index.

Unified constitutive laws of plastic deformation

Over the past few years, we have made numerous presentations, delivered several series of lectures, and participated in many discussions on the processes of time-dependent crack growth. We felt that the understanding of these processes had reached a degree of maturity: the basic physical principles were established and their application to engineering practice was now feasible. We concluded that the best way to organize this knowledge was to write it up in a single, coherent system. Martinus Nijhoff kindly encouraged us and generously offered their collaboration. Hence, this book. The physical process of time-dependent subcritical crack growth is rigorously defined by statistical mechanics. If well presented, the principles can be readily understood by practitioners of fracture research and design engineers. We present the physical processes of crack growth in terms of atomic interactions that assume only a working knowledge of the standard engineering materials course contents. From this, we develop a framework that is valid for any type of material, be it metallic, polymeric, ceramic, glass or mineral - indeed, any solid. We also assume an elementary exposure to fracture mechanics. An appendix is provided that outlines those aspects of fracture mechanics that are needed for an introduction to fracture kinetics analyses; it also provides a common ground for concepts and terminology (see Appendix A). We proceed through theory to applications that are of interest in research, development and design, as well as in test and operating engineering practice.

Fracture Kinetics of Crack Growth

The optimum design of manufacturing processes and of service performance requires economical methods for the stress analysis of plastic deformation. Stress analysis requires the establishment of the stress and strain rate (or strain) fields that result from the imposed forces and shape changes in a specific material. In three dimensions, there are six stress and six strain rate components determined from five rigorously defined conditions. These form a system of differential equations which, together with the forces and displacements applied at the boundary. Because all plastic deformation processes are temperature- and time-dependent, their behavior is described by the kinetics equation of the constitutive law. Temperature- and time-dependent behavior is the consequence of thermal activation. All thermally activated processes are expressed by the elementary rate constants combined in kinetics relations and derived from statistical mechanics.

A. S. Krausz

Papers

Unified constitutive laws of plastic deformation

Fracture Kinetics of Crack Growth

5 – The Constitutive Law of Deformation Kinetics

The theory of non-steady state fracture kinetics analysis—2: Non-steady state crack propagation in stress corrosion cracking

The theory of non-steady state fracture kinetics analysis—1: General theory of crack propagation