Fracture testing of spectacle lenses
(S Lucas and P Howlett)This problem was presented at MISG 2000 from the lens company SOLA International, with Jim Hill (University of Wollongong) and Steve Lucas as moderators.
The project involves theoretical work on the fracture of spectacle lenses when tested by either dropping a steel ball on them from a certain height, or applying a static load to the centre of the lens.
No one in the lens industry has done work in this area, and there is plenty of scope for analysis of the various features of this elasticity/fracture problem. Current work involves looking at contact problems between a sphere and a plate, and establishing the contact regions under deformation.