考虑参数非概率不确定性的碰摩转子非线性振动响应分析

Nonlinear vibration responses of a rubbing rotor considering the non-probabilistic uncertainty of parameters

转、静子碰摩故障严重影响燃气轮机运行安全性和可靠性,而非线性碰摩响应的不确定性是对其进行评估、预防或控制的重要制约因素。为此,考虑转静子间隙、转子不平衡量及接触刚度等参数的不确定性影响,建立含定点碰摩故障的燃气轮机双盘单轴转子不确定性动力学模型,研究碰摩振动响应特性及其参数影响规律。针对非光滑、不确定性转子碰摩动力学方程,利用谐波平衡法-时频域转换(HB-AFT)技术获取转子系统周期解,运用非嵌入式Chebyshev区间方法估计非线性振动响应的上、下界,从而快速量化各区间变量对响应不确定性的影响,并通过与传统Monte Carlo模拟对比验证了方法有效性和计算优势。数值结果表明,参数区间不确定性对碰摩转子全局幅频响应影响显著,可导致转/静子碰摩发生条件和严重程度的差异。研究结果可为燃气轮机转子碰摩故障提供参考依据。

The rotor/stator rubbing fault has a serious impact on the safety and reliability of a gas turbine,and the uncertainty of the nonlinear rubbing response is an important constraint for its evaluation,prevention,and control.Therefore,considering the uncertain effects of the rotor/stator clearance,rotor unbalance and contact stiffness,the uncertain dynamic model of a gas turbine dual-disk single-axis rotor with fixed-point rubbing faults was established to study the rubbing induced vibration response characteristics and its influential parameters.For the non-smooth/uncertainty rubbing dynamic equations,the combination of the harmonic balance method and the alternating frequency-time scheme(HB-AFT)was adopted to obtain the periodic solution of the rotor system,and the non-intrusive Chebyshev interval method was used to estimate the upper/lower bounds of the nonlinear vibration response.The influence of each interval variable on the response uncertainty could be quickly quantified.Finally,the effectiveness and computational advantages of the proposed method were verified by comparing with the traditional Monte Carlo simulation.The numerical results show that the uncertainty of the parameter interval has a significant effect on the global amplitude-frequency responses of the rubbing rotor,which can lead to differences in the occurrence conditions and severity of rotor/stator rubbing fault.The research results provide a guidance for more accurate diagnosis and prevention of gas turbine rotor rubbing faults.