Application of Photoelasticity to Fracture Mechanics

摘要

Preliminary experiments and results are presented for extending the photoelastic method to two-dimensional, inelastic problems such as would occur with the propagation of a crack. A brief review of fracture mechanics and photoelasticity is included. The effect of strain on birefringence, underconstant load, is shown for cellulose nitrate loaded inelastically. Values of Poissons ratio of greater than 0.5 are obtained during inelastic deformation. The strains were measured by means of Moire techniques. The design and operation of a 'coupled' polariscope which was constructed for this work is discussed. Some initial photographic results of two-dimensional elastic studies of crack propagation using a Q-spoiled ruby laser are included. (Author)