带凸肩叶片非旋转状态减振特性试验

Experiment of damping characteristic of non-rotating shrouded blade

设计了一套能够准确施加凸肩接触面正压力的非旋转状态带凸肩叶片减振特性试验系统,并对该系统的设计要求、正压力的加载方案以及试验误差进行了说明.利用该试验系统对不同激振力、不同初始正压力、不同凸肩接触角度和不同凸肩位置下叶片的一阶弯曲振动特性进行了测试,分析了凸肩接触面正压力、凸肩接触角度及凸肩位置等重要参数对凸肩结构减振效果的影响规律.试验结果显示,对一定的激振力存在一个最优的接触面初始正压力使得凸肩减振效果最好;凸肩接触角度和位置使凸肩接触面相对运动越大,凸肩的减振效果越好.

A measurement system was designed to accurately measure dynamic responses of non-rotating shrouded blade, in which initial normal load can be put on the friction interface by a load disc accurately. The design principle of this system, the loading scheme and the test errors were described. The dynamic response of the first bending mode of the shrouded blade with different shroud contact angles and shroud places were measured under various initial normal loads on the interface and different exciting force. The effects of the initial normal load, shroud contact angle and shroud place on the friction damping were analyzed from the test data. The results indicate that there is an optimal preload under which the shroud contact can provides maximal performance in dissipating vibratory energy for a given exciting force; and the relative displacement between the interfaces larger, the dissipating vibratory energy more. The design of shroud contact angle and place should obey this rule.