某APU负载压气机可调进口导叶失效机理研究

Study on Failure Mechanisms of Variable Inlet Guide Vane of an APU Load Compressor

针对某 APU 负载压气机可调进口导叶疲劳失效故障开展了故障原因分析,采用定常与非定常方法研究了工作角度变化对导叶稳态与交变气动载荷的影响规律,并在此基础上对导叶稳态应力和振动应力进行计算分析及测试验证。结果表明:可调进口导叶执行装置的“活塞杆”与“接耳”装配不到位,导叶角度严重偏离正常值,使得气动交变载荷显著增大,振动应力过大,从而导致导叶短时间内疲劳失效;导叶角度偏离提高了叶片的稳态应力水平,加剧了导叶的失效进程。建议完善相应的装配工艺,适当增大叶根圆角,以降低叶根的应力水平。

The cause analysis of fatigue failure was carried out for variable inlet guide vane of an APU load compressor. The influence law of working angle change on guide vane steady and alternating aerodynamic loads was studied by using steady and unsteady methods. On the basis of this,the calculation analysis and test verification were carried out for the steady-state stress and vibration stress of guide vane. The results show that the assembly of "piston rod" and "lug" of the variable inlet guide vane actuator are not in place. The angle of the guide vane deviates seriously from the normal value,which makes the aerodynamic alternating load increase significantly and the vibration stress is too large,which leads to the fatigue failure of the guide vane in a short period of time. The angle deviation of the guide vane increases the steady stress level of the vane and intensifies the failure process of the guide vane. It is suggested that the corresponding assembly process should be improved and the angle of the vane root should be increased properly,so as to reduce the stress level of the vane root.