基于多体接触瞬态动力学不对中故障模拟及试验验证

Misalignment Fault Simulation Method and Experimental Verification Based on Multi-body Dynamics with Transient Contact

提出一种基于多体接触瞬态动力学的转子系统不对中故障等效模拟分析方法,通过偏移(偏转)驱动转速,模拟各部件非线性接触运动产生不对中激励,分析了模拟方法的力学等效性。以典型电机-泵系统为对象,建立了多体动力学模型,获得了高次谐波及相应相位特征,研究了螺栓与半联轴器、滚动体与内外圈的瞬态接触力及箱体振动响应,得到了高次谐波特征产生机理及联轴器两侧振动相位特征。通过试验测试,验证了模拟分析方法模拟主要故障特征的正确性。结果表明:单个螺栓与半联轴器间的瞬态接触力是产生不对中故障特征的激励源;箱体振动响应频谱中除产生1、2倍频外,还产生3、4倍频等高次谐波;平行(角度)不对中时联轴器两侧径向2倍频(1倍频)相位差为180°(0°)左右,且随不对中量增大呈递减(递增)趋势;箱体振动仿真及测试结果的故障特征频率大小一致,各特征频率幅值相对大小、幅值随不对中量变化规律均具有较好的一致性。

An equivalent simulation and analysis method of rotor system misalignment fault based on multi-body dynamics with contact transient is proposed.By offsetting(deflecting) driving speed,the nonlinear contact motion of each component is simulated to generate misalignment excitation.The mechanical equivalence analysis of the simulation method is carried out.Taking the typical motor-pump system as the object,the corresponding multi-body dynamic model is established.Higher harmonics and corresponding phase characteristics are obtained.The transient contact forces of bolts,the half coupling,all rollers,the bearing inner and outer rings,and the vibration response of the box are studied.The generation mechanism of higher harmonics and the phase on both sides of the coupling are obtained.The correctness of the simulation analysis method is verified through experimental tests.The results show that the misalignment fault characteristics are from the transient contact force between a single bolt and the half coupling.In the vibration response spectrum of the box,in addition to the 1,2 frequency,there are also 3,4 frequency and higher harmonics.In case of parallel(angular) misalignment,the phase difference of radial 2 frequency(1 frequency) on both sides of the coupling is about 180 °(0 °),and it decreases(increases) with the increase of misalignment amount.The fault characteristic frequencies of the box vibration simulation and test results are consistent,and the relative magnitude of each its characteristic frequency amplitude and the variation law with the misalignment amount have a good consistency.