随机失谐叶盘系统受迫振动响应的统计特性研究

研究随机失谐对于具有循环对称周期结构的叶盘系统动力特性的影响.采用质量-弹簧组合系统模型和Monte Carlo方法,系统地研究失谐强度、耦合强度、阻尼、激振力阶次和叶片数等参数对于系统受迫振动特性的影响规律.计算结果表明,弱耦合系统比强耦合系统对失谐更加敏感,耦合强度的增加不一定导致系统振幅的降低.

STATISTICAL ANALYSIS OF THE FORCED RESPONSE OF RANDOM MISTUNING BLADED DISK

The statistical characteristics of the effects of random mistuning on the forced response of nearly cyclic assemblies is investigated. The Monte Carlo simulation is employed to generate the statistics of the N-DOF(N-degree of freedom) mass-spring model system. The effects of the system parameters on the expected value of the largest and mean amplitudes experienced by the assemblies at any excitation frequency are studied. The results show that weakly coupled systems are more sensitive to mistuning than strongly coupled ones leading a wider range of resonant frequency and an increase in the largest amplitude. But an increase in coupling strength does not necessarily lead to a decrease in the largest and mean amplitudes. Also, the effects of engine order and blade number are both weak in the weakly coupled system but opposite for the strongly coupled system. The damping ratio plays a positive role for suppressing forced response amplitudes in all conditions.