On probabilistic aspects in the dynamic degradation of ductile materials

Dynamic loadings produce high stress waves leading to the spallation of ductile materials such as aluminium, copper, magnesium or tantalum [1-3]. The main mechanism used to explain the change in the number of cavities with the stress rate is nucleation inhibition, induced by the growth of already nucleated cavities [4]. The dependence of the spall strength and critical time with the loading rate is investigated in the framework of a probabilistic model [4]. The present approach, which explains previous experimental findings on the strain rate dependence of the spall strength, is applied to analyze experimental data on tantalum [5]. \\[3pt] References: [1] Meyers M.A., Aimone C. T., 1983, ``Dynamic Fracture (Spalling) of Metals'', Prog. Mater. Sci., 18(1),pp. 1-96 [2] Curran D.R., Seaman L., Shockey D.A., 1987, ``Dynamic Fracture of Solids'', Phys. Rep., 147, pp. 253-388 [3] Grady D.E., 1988, ``The Spall Strength of Condensed Matter'', J. Mech. Phys. Sol., 36(3), pp. 353-384 [4] Trumel H., Hild F., Roy G., Pellegrini Y.-P., Denoual C., submitted to J. Mech. Phys. Sol., 2008. [5] Roy G., 2003, ``Vers une modelisation approfondie de l'endommagement dynamique ductile. Investigation experimentale d'une nuance de tantale et developpements theoriques'', Ph.D. Thesis, Poitiers University, France