Contact forces generated by hailstone impact

Abstract

Impact by hailstones can cause severe and widespread damage to roofs and many other exposed installations. This research aims at developing a model with which the value of the peak contact force generated by impact of a hailstone can be predicted with good confidence. A custom designed and built experimental setup involving the use of a gas gun for accurate measurement of contact force is first introduced. Some 45 impact experiments were conducted using the device. Meanwhile, an analytical spring connected lumped mass model featuring a non-linear visco-elastic compressive property of the frontal spring has been developed for simulating impact. To ensure that the analytical model is represent..