The Behaviour of Laminated and Toughened Glass under Impact by a Falling Bolt

JSGT 1945 V29 T197-T198

During a discussion on a paper by the author on the behaviour of laminated and toughened glass under impact at different velocities, Dr A. J. Holland raised the question of the relation between the radius of the impacting body to the ascertained strength of the glass. He suggested that the type of fracture obtained was a complex function of the impact energy, the radius of curvature, velocity of impacting body, as well as the dimensions of the glass specimen. In a private communication, Dr E. J. Gooding raised somewhat similar questions. The main point raised by Dr A. J. Holland and by Dr E. J. Goading could only be settled by experiment. For this purpose a suitable bolt was designed similar to that described by J. Wilson, so that a series of breaking experiments could be made at different velocities using an impacting surface with constant radius of curvature. Pieces of toughened and laminated glass were broken at constant energy as described below.

R. N. Haward