叶片飞失转子动力特性及支承结构安全性设计

针对航空发动机在叶片飞失极限载荷下的支点载荷控制问题,建立综合考虑冲击、惯性非对称、减速过临界等多种力学过程的支点动载荷响应分析方法;提出针对止推支点的缓冲阻尼支承结构安全性设计,该结构可以通过控制支承结构的刚度、阻尼参数,调整转子系统动力特性,降低转子临界转速。通过支点动载荷响应分析方法定量评估缓冲阻尼结构对降低支点动载荷的有效性。通过试验证明转子系统在冲击-减速过程中对支点载荷的影响因素。结果表明:叶片飞失所产生的冲击作用和减速过临界过程是威胁支承结构承载能力的主要因素。采用缓冲阻尼支承结构能够使叶片飞失下转子系统的支点动载荷降低至20%,是一种有效的支承结构安全性设计。

Dynamic characteristics of rotor and safety design of support structure with fan blade off

A pivot load response analysis method of comprehensively considering various mechanical processes, such as impact, inertia asymmetry, and deceleration over-critical for load control of aero engine under extreme load of blades off, was established. A safety design of buffer damping support structure for the thrust support was proposed, which can affect the dynamic characteristics of the rotor system by controlling the stiffness and damping parameters of the support structure, reducing the critical speed of the rotor. Quantitative evaluation of effectiveness for the buffer damping structure was carried out by the above pivot load response analysis method. The effects of pivot load during the impact-deceleration process was proved. Results showed that the impact effect and deceleration over the critical process caused by the blade off are the main factors that threaten the bearing capacity of the supporting structure. And the use of a buffer damping pivot structure can effectively reduce the pivot of the rotor system to 20% when fan blade off appeared, making it an effective design for the safety of the support structure.