基于时频域交互算法的干摩擦阻尼叶片稳态响应分析.pdfVIP

基于时频域交互算法的干摩擦阻尼叶片稳态响应分析 9F 基于时频域交互算法的干摩擦阻尼叶片稳 态响应分析 徐自力，刘雅琳 （西安交通大学能源与动力工程学院，710049，西安） 摘 要：引入了时频域交互算法来分析干摩擦阻尼叶片非线性动力系统的稳态响应，该方法利用了频域法 求解线性系统的高效性和在时域中表示非线性力的便捷性，采用离散傅立叶变换，将时域函数和频域函数 进行转换，通过反复的迭代最终得到动力系统的稳态解。文中将带干摩擦阻尼结构叶片简化为带理想弹塑 性阻尼器模型的单自由度系统，导出了采用时频域交互算法求解摩擦阻尼叶片稳态响应的具体公式和步骤。 算例表明：计算结果和 4 阶的龙格库塔法吻合较好，存在最优正压力使叶片系统响应最小，在正压力一定 的前提下，阻尼器的切向刚度增大有利于降低叶片的响应。该研究对阻尼结构叶片的动力学设计具有指导 意义。 关键词：叶片；干摩擦阻尼；非线性；时频域交互算法 Steady-State Response of Friction Damped Blade System Using a Alternating Frequency/Time Domain Method XU Zi-Li, LIU Ya-Lin (School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China) Abstract: The alternating frequency/time domain method (AFT) is introduced to solve the steady state response of the nonlinear dynamic system of damped blades. The method takes the advantages of both time domain method and frequency domain method, using discrete Fourier transform for alternating from the domain method to the frequency domain, by iterating to obtain the steady-state response of the system. Blade with idealized blade to ground damper is simplified as single mode model of blade with friction damper. Formula of friction force of damper and motion equation of system are developed. The forced response of the damped blade is studied using the AFT. The calculated result of steady response by the AFT agrees well with that by Runge-Kutta method. The effect of control parameters of the damper on steady state response of blade is discussed. Key words: blade; dry friction damping; nonlinearity; AFT. 引 言 在航空发动机和汽轮机上广泛地采用了带有阻尼围带、凸肩、或缘板阻尼器的叶片结构， 目的是为了利用接触界面干摩擦消耗振动能量，增加叶片系统的结构阻尼，减少叶片的强迫 振动响应，增加系统的稳定性。尽管采用干摩擦阻尼结构降低叶片振动响应的优点已经在工 程应用中得到了的证实，但是由于摩擦界面接触运动学的复杂性、干摩擦力的非线性，使