Theoretic analysis and numerical simulation on quantitative evaluation of interface strength by pulsed-laser technology

摘要

Abstract: With the aim of quantitative measuring the dynamic adhesive strength of Al$-2$/O$-3$/film/Fe, we use a modified laser spallation setup, and let high-power laser pulse shock the energy absorbing thin coating, then cause a pressure pulse propagating to matrix. At the free surface, a laser probe is used to record the epicentral surface displacement history caused by elastic wave which propagating to the free surface. Though the analysis of elastic wave, data processing and a computer simulation, we propose a novel model of the attenuation and the dispersion of the elastic wave. After characterizing, we obtain a new spallation criteria corresponding to progressive damages at the film- matrix interface, i.e. interface delamination, film spallation and film expulsion, respectively. At the same time, according to the arrival time and attenuation pattern of the elastic wave, we also propose a new computer algorithm for estimating the source fracture dimension.!10