【摘要】 通过研究碰摩声发射波中的模态特征,为判断碰摩状态及识别碰摩信号与噪声提供依据.在静态下进行试验以获得纯净的碰摩信号,在转子试验台的碰摩源分别施加碰撞力和摩擦力,对这2种力激励的近似原始声发射波的模态成分以及这2种类型波经过一段距离传播后的特征进行了分析.在动态时模拟不同程度的碰摩故障,结合静态时得到的分析结论对其声发射信号谱进行判断.试验结果表明,碰撞力主要激励弯曲波,摩擦力主要激励高频低能扩展波和部分高频弯曲波.在实际的碰摩故障中,随着碰摩的发展其激励的声发射波的模态成分随之变化,因此,通过对声发射信号频谱的变化特征可以判断出碰摩状态和发展趋势.更多还原

【Abstract】 According to the analysis of the modal characteristic in rub-impact acoustic emission(AE),effective evidence of estimating rub-impact state and distinguishing rub-impact from noise can be provided.Rub-impact signal was sampled at static condition to avoid disturbing by noise.Rub force and impact force were imposed at rub-impact source in the rotating test stand separetely.Each model composition of the original AE waveform excited by different force was analyzed.The characteristic of each kind AE waveform after propagating some distance was also analyzed.Finally the rub-impact fault with different intensity was simulated at dynamic condition,and the conclusion acquired in static condition was used to analyze AE spectrum.The experimental results indicate that the flexural wave is excited by impact force;expansion waves and part of high frequency flexural waves are mainly excited by rub force.The compositional modes of AE waveform change along with the development of rub-impact fault.So,through analyzing the modal of acoustic emission signal,the impact-rub state and its development trends can be estimated by the dynamic features of AE spectrum.更多还原