连接件松动的非同步振动响应特征分析与验证-工程力学.PDF

第 33 卷第 4 期 Vol.33 No.4 工 程 力 学 2016 年 4 月 Apr. 2016 ENGINEERING MECHANICS 225 文章编号：1000-4750(2016)04-0225-08 连接件松动的非同步振动响应特征分析与验证 王海飞，陈 果 (南京航空航天大学民航学院，南京 210016) 摘 要：针对普遍存在的航空发动机连接件松动故障现象，建立了单自由度集总质量模型，引入松动故障模型， 利用数值积分方法求得系统响应，分析了非同步响应特征；利用对含松动间隙的连接件进行松动实验，发现了其 加速度响应经过自相关降噪后，时域波形表现为明显的冲击特征，波形上下不对称，呈现“截头状”波形；频谱 上表现为伪临界亚谐共振以及伪临界超谐共振；此特征与仿真结果一致，可以作为判定松动故障的典型特征。通 过仿真发现，导致连接件出现该松动特征的原因在于：1) 松动故障引起的刚度的变化；2) 当刚度变化的周期等 于振动周期时，将产生倍频现象，在特定频率下，将激发系统的临界频率；当刚度变化的周期等于 n 倍振动周期 时，则将产生 1/n 分频及其倍频，在特定频率下，将激发系统的临界频率。 关键词：动力学模型；非同步响应特征；自相关降噪；松动故障；松动特征 中图分类号：V231.9 文献标志码：A doi: 10.6052/j.issn.1000-4750.2014.08.0729 ASYNCHRONOUS VIBRATION RESPONSE CHARACTERISTICS OF CONNECTORS WITH LOOSENESS FAULT AND ITS VERIFICATION WANG Hai-fei , CHEN Guo (College of Civil Aviation, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China) Abstract: For the universal phenomenon of aero-engine connectors with looseness fault, a single degree of freedom lumped mass model was established and a looseness fault model was introduced. The response of the system was obtained by numerical integration methods and the asynchronous response characteristics are analyzed. The experiments were conducted on the connectors with looseness clearances. It is found that the acceleration response of a mass block after noise reduction has up-down asymmetrical impact characteristics in a waveform, also the pseudo-critical subharmonic resonance and the pseudo-critical ultra-harmonic resonance appear in a frequency spectrum