Z型航空液压管道布局参数对其模态特性影响研究
Influence of Layout Parameters of Z-Layout Aircraft Hydraulic Pipeline on its Modal Characteristics

飞机液压管道系统存在大量用来连接两个轴向错位接头的Z型管道，不同布局的Z型管道具有不同的模态特性。Z型管道布局由弯头位置及弯管曲率半径这两个参数确定。通过模态试验结合数值仿真研究这两个布局参数对管道模态特性的影响规律。研究发现，Z型管道的1阶模态出现在垂直于管道平面方向上，2阶模态出现在管道平面。当弯头位置从靠近一端接头变化到与两端接头距离相等的位置时，管道的1阶固有频率增大，而2阶固有频率减小；当曲率半径增大时，管道的低阶固有频率都增大。
Z-layout pipelines used to connect two parallel pipe-joints numerously exist in aircraft hydraulic piping system. Different layout pipelines have different modal characteristics. The design of Z-layout pipelines is determined by two parameters:the location of the elbow and the radius of curvature. The effects of these two design parameters on the modal characteristics of pipeline are studied by experiments and the numerical simulations. Results indicate that the first mode appears in the direction perpendicular to the layout plane and the second mode appears in the layout plane of the Z-layout pipelines. The first natural frequency increases while the second natural frequency decreases when the location of the elbow changes from one end to the mid-point between the two joints and the natural frequencies increase with the increasing of radius of the elbow