Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-09T07:14:51.515Z Has data issue: false hasContentIssue false

Scale-invariant initial value problems in one-dimensional dynamic elastoplasticity, with consequences for multidimensional nonassociative plasticity

Published online by Cambridge University Press:  16 July 2009

David G. Schaeffer
Affiliation:
Department of Mathematics, Duke University, NC 27706, USA
Michael Shearer
Affiliation:
Department of Mathematics, North Carolina State University, NC 27607, USA

Abstract

This paper solves a class of one-dimensional, dynamic elastoplasticity problems for equations which describe the longitudinal motion of a rod. The initial conditions U(x, 0) are continuous and piecewise linear, the derivative ∂U/∂x(x, 0) having just one jump at x = 0. Both the equations and the initial data are invariant under the scaling Ũ(x, t) = α−1U(αx, αt), where α > 0; hence the term scale-invariant. Both in underlying motivation and in solution, this problem is highly analogous to the Riemann problem from gas dynamics. These ideas are applied to the Sandler–Rubin example of non-unique solutions in dynamic plasticity with a nonassociative flow rule. We introduce an entropy condition that re-establishes uniqueness, but we also exhibit problems regarding existence.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Antman, S. & Szymczak, W. 1989 Nonlinear elastoplastic waves. Contemp. Math. 100, 2754.CrossRefGoogle Scholar
[2] Barenblatt, G. I. 1952 On self-similar motions of a compressible fluid in a porous medium. Prikl. Math. Mech. 16, 679698 (in Russian).Google Scholar
[3] Christoffersen, J. & Hutchinson, J. 1979 A class of phenomenological corner theories of plasticity. J. Mech. Phys. Solids, 27, 465487.CrossRefGoogle Scholar
[4] Clifton, R. & Bodner, S. 1966 An analysis of elastic-plastic pulse propagation. J. Appl. Mech. 33, 248255.CrossRefGoogle Scholar
[5] Courant, R. & Friedrichs, K. 1948 Supersonic Flow and Show Waves. New York: Interscience.Google Scholar
[6] Darve, F. 1990 Incrementally nonlinearconstitutive relationships. In Geomaterials: Constitutive Equations and Modelling (ed. Darve, F.), London: Elsevier.CrossRefGoogle Scholar
[7] Duvaut, G. & Lions, J. L. 1976 Inequalities in Mechanics and Physics. New York: Springer.CrossRefGoogle Scholar
[8] Gel'fand, I. M. 1963 Some problems in the theory of quasilinear equations. AMS Trans. 29 (2), 295381.Google Scholar
[9] John, F. 1982 Partial Differential Equations. New York: Springer.CrossRefGoogle Scholar
[10] Kevorkian, J. & Cole, J. 1981 Perturbation Methods in Applied Mathematics. New York: Springer.CrossRefGoogle Scholar
[11] Lax, P. D. 1957 Hyperbolic systems of conservation laws II. Comm. Pure Appl. Math. 10, 537566.CrossRefGoogle Scholar
[12] Lee, E. 1952 A boundary value problem in the theory of plastic wave propagation. Quart. Appl. Math. 10, 335346.CrossRefGoogle Scholar
[13] Nouri, A. 1991 Problémes hyperboliques en élasto-plasticité dynamique. Thesis in Applied Mathematics, University of Nice.Google Scholar
[14] Rudnicki, J. & Rice, J. 1975 Conditions for the localization of deformation in pressure-sensitive dilatant materials. J. Mech. Phys. Solids 23, 371394.CrossRefGoogle Scholar
[15] Sandler, I. & Rubin, D. 1987 The consequences of non-associated plasticity in dynamic problems. In Constitutive Laws for Engineering Materials: Theory and Applications (eds. Desai, C. S. et al. ), New York: Elsevier.Google Scholar
[16] Schaeffer, D. & Shearer, M. 1990 Loss of hyperbolicity in yield vertex plasticity models under nonproportional loading. In Nonlinear Evolution Equations that Change Type (eds. Keyfitz, B. & Shearer, M.), New York: Springer.Google Scholar
[17] Shearer, M. & Schaeffer, D. The Initial Value Problem for a System Modelling Unidirectional Longitudinal Elastic-Plastic Waves. Preprint.Google Scholar
[18] Smoller, J. 1983 Shock Waves and Reaction-Diffusion Equations. New York: Springer.CrossRefGoogle Scholar
[19] Témam, R. 1985 Mathematical Problems in Plasticity. Paris: Bordas.Google Scholar
[20] Trangenstein, J. & Pember, R. 1991 The Riemann problem for longitudinal motion in an elastic-plastic bar. SIAM J. Sci. Stat. Comp. 12, 180207.CrossRefGoogle Scholar
[21] Xu, X.-P., Ortiz, M. & Needleman, A. 1991 Computational methods for localization problems. Proc. 15th Conference on Th. Appl. Mech. (SECTAM). Georgia Tech, USA.Google Scholar