论文部分内容阅读
本文以紧凑拉伸Q245R焊接试样为研究对象,利用特征参数法分析了焊缝缺口根部塑性阶段、微裂纹萌生以及裂纹失稳扩展阶段的声发射信号关联特征和累积声发射特性。同时采用小波分析中的sym5小波对弹性阶段和塑性阶段的声发射信号进行5级小波分解,计算出信号的能量值主要集中在d4、d5和a5级;弹性阶段的声发射信号主要集中在低频部分,塑性阶段的声发射信号开始向高频部分集中,而且各级信号的标准偏差均低于10%。
In this paper, a compact tensile Q245R welded specimen was taken as the research object. The characteristics of acoustic emission signal and cumulative acoustic emission were analyzed by the characteristic parameter method in the plastic phase, micro-crack initiation and crack instability propagation. At the same time, the wavelet analysis of the sym5 wavelet elastic and plastic phase of the acoustic emission signal by five wavelet decomposition, calculated the energy of the signal mainly in the d4, d5 and a5 level; elastic phase acoustic emission signals are mainly concentrated in the low frequency Partially, the acoustic emission signals from the plastic phase started to concentrate toward the high frequency part, and the standard deviation of the signals at all levels was below 10%.