Transient waves in a compliant cylindrical cavity enclosing comminuted material

An acoustic model is presented for analyzing transient waves from impact on a mass of confined comminuted material. Two approaches are considered: a modal approach utilizing the static-dynamic superposition method, and a finite difference approach. For prescribed motion at the footprint, analysis proceeds by superimposing response from several external annular segments of unit pressure gradient and with time-dependent weights yielding a combined response equal to the prescribed instantaneous motion. Pressure histories from the two approaches are in agreement. The effect on response of prescribed motion parameters and wall mobility is studied.