柔性转子动力学特性及支承结构安全性设计

叶片飞失极限状态下,航空发动机转子系统承受冲击载荷和大不平衡载荷,载荷通过转子结构传递到支承结构,对支承结构造成严重损伤。从安全性的角度看,需要对航空发动机轴承-支承结构在极限载荷下的承载能力进行有效的定量评估。提出一种新型缓冲阻尼支承结构,通过对支点刚度突降和高阻尼设计,实现在止推轴承支点处大幅降低横向冲击载荷的影响。建立考虑支承结构刚度突变和阻尼特性的转子系统动力学方程,并计算突加不平衡激励下,转子系统支点动载荷分布的变化规律。结果表明:通过优化设计支点刚度和阻尼参数,缓冲阻尼支承结构,能够有效降低突加不平衡激励下止推滚珠轴承的支点动载荷,提高支承结构的安全性。

Aeroengine Flexibility Rotor Dynamics and Support Structure Safety Design

In the extreme condition(fan blade off),the aeroengine rotor system was subjected to huge loads(such as impact loads,large unbalanced loads),causing serious damage to the support structure.From the perspective of safety,it was necessary to design the support structure to ensure the capacity of windmill operation under extreme loads.A new type of buffer-damp support structure was proposed.The dynamic equation of the rotor system considering the buffer-damp support structure was established.The numerical integration method was used to calculate the dynamic characteristics of the rotor system with buffer-damp support structure.The results show that the buffer-damp support structure can effectively reduce the support dynamic load for the rotor system under suddenunbalanced excitation,which is an effective design of support structure safety.