EXPERIMENTAL-DETERMINATION OF STRESS INTENSITY FACTORS BY CAUSTICS

This paper describes the application of the caustic method in fracture mechanics for determination of stress intensity factors of mechanically isotropic materials. The equations for mode I crack opening are expressed for optical effect in the transparent and reflective light and applied in the given experimental results for standard specimen. The problem of determination of the constants of caustics is solved by relating the optical constant of caustics with the photoelastic constant of the optically anisotropic material. This algorithm eliminates the deficiency of a additional criteria for choosing the prevailing state of stress and strain near the crack-tip.