Kinetics Modeling Under Shock-Loading Conditions

Shock loading induces complex kinetic processes leading to such macroscopic phenomena as plastic deformation, phase transformations, and spall. The associated rates are typically modeled as first-order processes. The form of any rate constant is then assumed to be of an Arrhenius form [1]. This form of rate law assumes an equilibrium distribution of velocities in the system [2]. Clearly, in a shock-loaded system, the velocity distribution needs to be centered on the particle-velocity, u$_p$ [3]. A revision in the Arrhenius rate model leads to u$_p$-dependent rate constants. At high shock loading, the rate constant naturally switches to a power-law dependence in keeping with observation. \newline [1] D. L. Preston, D. Tonks, and D. C. Wallace, J. Appl. Phys. 93, 211 (2003). \newline [2] H. A. Kramers, Physica (Amsterdam) 7, 284 (1940). \newline [3] S. M. Valone, J. Chem. Phys. 118, 9606 (2003).