A New Conceptual Model to Describe Spallation

A new conceptual model to describe spallation was presented basing on the original Cochran-Banner spall model. The strength function given by Cochran-Banner was maintained using the redefined damage, and the correction concerning the volume of the mesh cells was realized considering it unnecessary to expect that it is much easier to open microcracks once they are formed than to strain the solid further. Once the spall strength was reached, the damage in the new conceptual spall model would be only determined by a series of closed equations including the stress relaxation relationship given by the strength function, the energy conservation equation, the equation of state, and the constitutive equations for the damaged aggregate. The new conceptual spall model contains only two parameters: the spall strength and the critical damage, the determination of which should make the computed results of spall tests under the appropriate initial and boundary conditions consistent with the experimental free surface velocity profile of target or the stress profile of interface between target and low impedance buffer and the observed damage at spall plane for spall tests. It is worth to note that choosing a strength function or a stress relaxation equation provides a possibility of determining the damage and excludes any extra equation of damage evalution.