某型直升机发动机排气机匣振动问题分析与处理

Analysis and Treatment of the Vibration Problem of XX Helicopter Engine Exhaust Box

某型直升机在外场飞行过程中,出现左发排气机匣振动偏大的问题。通过飞行振动数据分析,理论分析,有限元仿真分析,同时结合动特性试验结果,确定了故障是由于传感器安装支座尺寸超差导致传感器安装频率靠近激励频率引起的。基于分析和试验结果并结合现场情况,提出了更换满足要求的传感器安装支座的解决措施,并对传感器安装支座提出了相应的设计改进建议。更换传感器安装支座后,经飞行验证该发动机排气机匣飞行振动水平显著下降,表明该故障原因定位准确,解决措施有效。

The vibration problem of the XX helicopter left engine exhaust box was occurring during the flight training.In this paper,through the flight vibration dataanalysis,theoretical analysis,finite element analysis and dynamic test,it was determined that the fault was caused by the sensor mounting frequency close to the excitation frequency due to the size difference of the sensor mounting support.Based on the analysis and test results,combined with the field situation,the measure of replacingsensor mounting support was putted forward,and further the design improvement suggestions for the sensor mounting support were putted forward.After replacing the mounting support of the sensor,the vibration level of the exhaust box of the left engine was significantly reduced,which showed that the fault cause was located accurately and the solution was effective.