Application of Scattering Theory to Plastic Strain Estimation

Abstract

Light scattering theory and plastic deformation induced surface roughening were studied in an effort to provide some theoretical background to a nondestructive, non-contact plastic strain evaluation method. Experimental investigation shows that plastic strain on the surface of a metallic specimen is linearly proportional to surface root-mean-square roughness and inversely proportional to surface profile correlation length. Utilizing these relations along with Beckmann’s light scattering theory, we obtained an expression which describes the scattered light intensity distribution in terms of plastic strain. This expression was applied to plastic strain evaluation and favorably verified by some experiments on aluminum alloy and brass materials.