The Optical Methods of Caustics and Photoelasticity: A Comparison

摘要

The optical methods of photoelasticity and caustics have extensively been used for the determination of stress intensity factors (SIFs) in static and dynamic crack problems. Both methods present their potentialities and limitations. In crack problems the state of stress in the neighborhood of the crack tip changes from plane strain near the tip to plane stress away from the tip through an intermediate three-dimensional region. This affects the determination of SIFs using experimental methods. In the present work the methods of photoelasticity and caustics applied to crack problems are briefly presented and compared regarding the following criteria: the optical set-up, the efficiency in the determination of stress intensity factors, the effect of crack tip radius, the effect of plate boundaries, the location of the crack tip and the changing state of stress near the crack tip.