Experimental and theoretical technique for studying local plastic zones near cracks

Microhardness measurements have been employed for studying zones of plasticity at the surface and in the bulk of a material. Stress intensities are estimated and their distribution in the plastic zone near the crack tip is established. The size of plastic zone at the crack front has been found from microhardness measurements. By solving the corresponding boundary-value problems of the theory of plastic flow in heterogeneous solids, stresses in the vicinity of the crack tip at plane deformation have been estimated