某型发动机支承松动故障机理分析与试车数据验证

摘要

Certain missile turbofan engine vibration was over standard , so a one-dimensional finite ele-ment beam model was established to simulate .The data from test were combined for fault analysis and simulation ,which was verified that there was critical speed at working speed .Loosen fault would be excit-ed under larger unbalanced force.In this paper ,shock features of asymmetric stiffness model to casing ac-celeration signal were analyzed ,discovering that looseness would lead to asymmetrical features of accelera-tion time domain wave and multiple frequency features of frequency spectrum ,which was consistent with the data from test .Asymmetric stiffness looseness model was verified to be more fit for aeroengine loose-ness fault model .The results show vibration fault is caused by improper support stiffness ,which leads to looseness fault near the critical speed .%针对某型弹用涡扇发动机振动超标问题，建立了一维有限元梁模型进行仿真与模拟，结合实际试车数据进行了故障分析和仿真，验证了故障原因在于工作转速内存在临界转速，在较大的不平衡力作用下，松动故障被激发。针对机匣加速度信号，研究了不对称刚度模型下松动故障的冲击特征，发现了松动故障所引发的机匣加速度时域波形特征的不对称性以及频谱中出现倍频特征，与实际弹用涡扇发动机试车数据非常一致。结果表明：振动故障是由于支承刚度不足，导致在临界转速附近出现松动故障。