冲压发动机管路断裂故障分析及结构改进  

Failure analysis and structure improvement of pipeline fracture for ramjet engine

作　　者：石波 戴进 樊根民 SHI Bo;DAI Jin;FAN Genmin(Xi'an Aerospace Propulsion Institute, Xi'an 710100, China)

机构地区：[1]西安航天动力研究所,陕西西安710100

出　　处：《火箭推进》2021年第1期43-48,共6页Journal of Rocket Propulsion

基　　金：国家自然科学基金青年项目(11702205)。

摘　　要：针对发动机管路系统断裂故障,开展故障机理分析。通过软件仿真和试验相结合的结构模态分析,找出模态振型与疲劳破坏的联系,对管路结构断裂故障原因进行初步定位和定性分析。利用ANSYS nCode DesignLife软件对结构开展随机振动疲劳寿命计算,总结了随机振动疲劳计算流程和设计方法。仿真预示的管路结构断裂位置与试验结果基本一致。提出多个结构改进方案,利用振动疲劳仿真计算对不同改进结构进行定量的疲劳寿命预测,优选出最佳方案。优化方案提高了管路结构的抗振性能,降低了RMS应力值和损伤,在主要破坏工况(x向振动)疲劳损伤寿命提高到3.2×107 s,其余振动方向疲劳损伤寿命分别提高到202%(y向)和190%(z向)。通过试验考核验证改进措施有效。The fracture failure occurring in a pipeline vibration experiment is analyzed in this paper. Through the structure modal analysis combining simulation and experiment, the immanent relationship between modal shape and random vibration destruction is deduced, and the causes of pipeline failure are preliminarily located and qualitatively analyzed. Based on ANSYS nCode DesignLife software, the random vibration fatigue calculation of pipeline is carried out, and the calculation process and design method of random vibration fatigue are summarized. The fracture position predicted by the simulation is basically consistent with the experimental results. Vibration fatigue simulation is used to quantitatively predict the fatigue life of several improved structures to obtain the best scheme. The optimization scheme improves the anti-vibration performance of the pipeline structure and reduces RMS stress value and damage. The fatigue damage life of the optimization scheme is increased to 3.2×10^7 seconds under the main failure condition(x-direction vibration), and 202%(y-direction vibration)and 190%(z-direction vibration) in other directions, respectively. The effectiveness of the improvement measures is verified by the test.

关 键 词：冲压发动机 管路断裂 模态振型 随机振动疲劳 

分 类 号：V343.23[航空宇航科学技术]