航空发动机旋转叶片-机匣碰摩动力学特性研究

Study on Rubbing Dynamic Characteristics of Aero-engine Rotatingblade-casing

利用谐波平衡法,采用隐式-显式相结合的分析方法,分别通过理论分析和有限元分析对转子-盘片-机匣耦合系统进行碰摩动力特性和响应特征研究。研究发现碰摩产生的应力波在叶身方向传导,碰摩开始时叶尖应力最大,碰摩结束时叶根应力最大;首次碰撞的叶片碰摩力最大,机匣吸能最多,依次递减;单个叶片碰摩后,主要以低阶固有模态频率做振动衰减;轴心轨迹在较大转速下,有无碰摩状况对其整体轨迹形状影响不大。这些研究结论和研究方法对于深入认识叶片-机匣碰摩的物理现象和工程中碰摩现象的故障诊断具有一定参考价值。

The dynamic characteristics and response characteristics of rotor- bladecasing werestudied through theoretic analysis and finite element analysis, using harmonic balance method. The research show that the stress waves produced by rubbing are in the direction of the blade body. The tip stress is the grea- test when the rub starts, and the maximum of the blade stress become the root of the blade at the end of rub. These research findings and research methods may provide some reference for the design of damping- structure. The first impact of the blade rubbing force is greatest, while the casing suction energy is the most, descending in descending order. Vibration of a single blade attenuates by with a low order natural modal frequency. There is no impact on the overall trajectory shape of the axial trajectory under the larger rotational speed. These conclusions and research methods have a certain reference value for deeply under- standing the physical phenomena of blade- casing rubbing and the fault diagnosis of rub- impact phenom- enon in engineering.