Crack Detection in Formed Sheet Metal by Acoustic Emission

摘要

The acoustic emission method was applied to detect crack initiation under fatigue loading in a formed sheet metal automotive component. A feasibility study was undertaken to evaluate the effectiveness of the method. A number of tests were conducted to improve the sensitivity and repeata-iility of results. The specimen geometry and testing procedure were designed to simulate service conditions. Two sets of tests were conducted at two different cyclic amplitudes. Four transducers arranged near the formed area were used to improve the accuracy and sensitivity of the system. It was shown that the history plots with the peak value of the parameter recorded are useful in determining crack initiation and propagation in a noisy environment. The results showed consistency and reliability and prove that the acoustic emission technique is a suitable tool for real time inspection.