带有阻尼环(套)的篦齿封严装置固有特性的理论及实验

Theoretic and experimental modal analysis of labyrinth air seals with damping-ring/sleeves

以带有开口阻尼环(套)的篦齿封严装置为研究对象,运用弹性力学、材料力学和接触力学的有关理论研究了阻尼环(套)与封严装置之间的接触压力和接触刚度的求解方法.在此基础上,根据结构系统动力学理论建立了封严装置/阻尼环(套)组合结构的等效线性系统模型,并通过模态实验验证了理论模型的正确性.研究了阻尼环的安装位置和阻尼套厚度、宽度、开口量等参数对组合结构固有特性的影响规律.阻尼环在不同的安装位置时对封严装置固有特性的影响较小.阻尼套对封严装置固有特性的影响包括附加质量和附加刚度两方面,当封严装置结构一定时,组合结构的固有频率与封严装置自身频率的差异大小取决于阻尼套附加质量和附加刚度的相对比较.由于阻尼环(套)开口较小,并且它的刚性远低于封严装置的刚性,组合结构仍大致以周波型振动为主.

Modal analysis of contact system is complex due to its non-linear and chaotic behaviors in the process. This paper builds up the equivalent linear model of labyrinth air seals with damping-ring/sleeves by introducing local contact stiffness and using vibration mechanic theory. The experimental results of natural frequencies and mode shapes of the labyrinth air seals with damping-ring/sleeves verified the validity of the proposed simplified model and the simulation results by finite element method（FEM）. The influence of variable parameters （position, width, thickness and gap size） of damping-ring/sleeves are also studied.