Further reflections on the calibration of hailpads

Abstract

A model for the collision of hailstones with foamed plastic materials is presented both for the case of normal incidence and for oblique incidence (wind‐blown hailstones). Some of the consequences and predictions of the theory are explored both analytically and by means of numerical integration of the equations of motion. The results of the theory are compared and found to be in acceptable agreement with empirical data obtained by dropping steel spheres simulating the impact kinetic energy of hailstones at terminal velocity onto styrofoam hailpads of the type used in the Alberta Hail Project.