梁结构碰撞位置的定量诊断方法
Quantitative Diagnosis Method for Impacting Locations in Beam Structure

针对机械设备中广泛存在的各种梁结构常因振动等原因与外界发生碰撞而不能及时准确检测出碰撞位置的问题，提出了一种梁结构碰撞故障位置的定量诊断方法。基于谐波平衡理论推导出碰撞梁响应信号中高次谐波成分之间的对比关系，根据故障系统和故障系统信号的响应之差，提取某一高阶谐波分量，结合梁结构系统的有限元模型来诊断碰撞故障的具体位置。对悬臂梁和复杂梁结构的数值仿真和实验结果显示，该诊断方法能够准确判断梁结构的碰撞故障位置。通过改变未知参数的实验表明，该方法具有较好的稳健性，不需要大量的先验数据，仅用两个测点的响应数据就可以诊断出故障的准确位置，简单又便于实现在线诊断。
The beam structures that commonly exist in mechanical machineries are often impacted by vibration, the location of which was difficult to detect. A quantitative diagnostic method for rubbing location detection in a beam structure is thus proposed. The relationship between the high order harmonic components of the responses of the impacting beam was deduced based on the harmonic balance theorem. Harmonic components of the response difference between the fault and pre-fault system combined modal of beam structure were used to detect the impacting locations. Numerical simulations and experiments on the cantilever beam and complex beam structure show that the rubbing fault location was accurately detected, and the experiments that changed the damping matrix show that the method was rather robust. The advantage of this method is that the impacting location can be diagnosed with responses of only two nodes, and plenty of prior data was not needed, so this method was easy to apply in online diagnoses.