论文部分内容阅读
在20℃至-55℃下对16MnR材料进行Charpy冲击试验,用声发射技术监测各温度下冲击开裂的过程。采用小波分析结合傅里叶变换的方法,得到了16MnR试样开裂过程的波形频谱特性及电压幅值,并且采用金相和SEM对冲击断口进行了组织、形貌分析。结果表明:随着温度的下降,声发射计数率、声发射能量及声发射持续时间均呈降低趋势,声信号幅值变化不大。小波分解后的d2层能量包含冲击断裂的主要能量,与冲击功的变化趋势相似,具有较强的相关性。试验结果为声发射技术监测冲击载荷作用下的材料内部结构演化提供了一个思路。
The Charpy impact test was performed on 16MnR material at 20 ° C to -55 ° C and the acoustic rupture process was monitored using acoustic emission techniques at various temperatures. The wave spectrum characteristics and voltage amplitude of 16MnR sample were obtained by wavelet analysis combined with Fourier transform. The microstructure and morphology of the impact fracture were analyzed by metallography and SEM. The results show that as the temperature decreases, the acoustic emission count rate, acoustic emission energy and acoustic emission duration decrease, and the amplitude of acoustic signal does not change much. The energy of the d2 layer after wavelet decomposition contains the main energy of impact fracture, which is similar to that of impact energy and has a strong correlation. The test results provide a train of thought for the acoustic emission technology to monitor the evolution of the internal structure of the material under impact loading.