A ballistic material model for starphire®, a soda-lime transparent-armor glass

Experimental observations pertaining to the damage evolution in Starphire®, a soda-lime transparent-armor glass, made in the recent work of Strassburger et al. [E. Strassburger, P. Patel, J.W. McCauley, C. Kovalchick, K.T. Ramesh, D.W. Templeton, Proceedings of the 23rd International Symposium on Ballistics, Spain, April, 2007; E. Strassburger, P. Patel, J.W. McCauley, D.W. Templeton, Proceedings of the 23rd International Symposium on Ballistics, Spain, April, 2007] in a series of edge-on-impact (EOI) tests and other open literature experimental findings are used to construct a (high strain-rate, high-pressure, large-strain) ballistic constitutive model for this material. The basic components of the model are constructed in such a way that the model is suitable for direct incorporation into typical transient non-linear dynamics finite element-based software packages like ANSYS/Autodyn [ANSYS/Autodyn version 11.0, User Documentation, Century Dynamics Inc. a subsidiary of ANSYS Inc., 2007] or ABAQUS/Explicit [ABAQUS version 6.7, User Documentation, Dessault Systems, 2007]. To validate the material model, a set of finite element analyses of EOI tests was carried out and the computational results compared with their experimental counterparts. It is found that front-shapes and propagation velocities of the longitudinal and transverse waves are quite well represented by the model. The same was found to be the case for front-shapes and propagation velocities of the “coherent-damage” zones but mainly at shorter post-impact times. Discrepancies at longer post-impact times are attributed to the effects of damage-promoting target-fixturing-induced stresses and cutting/grinding-induced flaws.