“…Smooth convolution kernels with one derivative bounded at 0 yield hyperbolic behavior in the sense that singularities are propagated much as in the purely elastic case, although they are exponentially damped (e.g., see [1,6,7,9,10,12,17,23,25]). However, recent literature indicates that many materials may be better described by equations involving singular kernels, such as fractional derivative models [2,3,26].…”