FREE VIBRATION ANALYSIS AND PHYSICAL PARAMETER IDENTIFICATION OF NON-UNIFORM BEAM CARRYING SPRING-MASS SYSTEMS  

变截面梁弹簧质量系统自由振动分析与物理参数识别(英文)

作　　者：马蕾[1,2] 芮筱亭[1] Abbas Laith 杨富锋[1] 张建书[1] 

机构地区：[1]南京理工大学发射动力学研究所 [2]上海卫星装备研究所

出　　处：《Transactions of Nanjing University of Aeronautics and Astronautics》2012年第4期345-353,共9页南京航空航天大学学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(10902051);the Natural Science Foundation of Jiangsu Province(BK2008046)~~

摘　　要：To analyze a multibody system composed of non-uniform beam and spring-mass subsystems, the model discretization is carried on by utilizing the finite element method（FEM）, the dynamic model of non-uniform beam is developed by using the transfer matrix method of multibody system（MS-TMM）, the transfer matrix of non-u- niform beam is derived, and the natural frequencies are computed. Compared with the numerical assembly method （NAM）, the results by MS-TMM have good agreement with the results by FEM, and are better than the results by NAM. When using the high precision method, the global dynamic equations of the complex multibody system are not needed and the orders of involved system matrices are decreased greatly. For the investigation on the re- verse problem of the physical parameter identification of multibody system, MS-TMM and the optimization tech- nology based on genetic algorithms（GAs） are combined and extended. The identification problem is exchanged for an optimization problem, and it is formulated as a global minimum solution of the objective function with respect to natural frequencies of multibody system. At last, the numerical example of non-uniform beam with attach- ments is discussed, and the identification results indicate the feasibility and the effectivity of the proposed aop- proach.为了研究变截面梁弹簧质量系统,通过有限元思想对模型进行离散化,应用多体系统传递矩阵法建立该系统动力学模型,推导变截面梁的传递矩阵,并计算了系统的固有频率。该方法计算结果优于数值拼装法(Numerical assembly method,NAM)计算结果,更接近高精度的有限元仿真结果。而且采用该方法,无需建立系统动力学方程并且可降低涉及矩阵阶次。为了研究多体系统物理参数识别反问题,将多体系统传递矩阵法与遗传算法相结合,将物理参数识别问题转化为参数优化问题,建立与系统固有频率相关的全局最小量作为目标函数。最后给出了数值算例,结果说明了该方法的可行性和有效性。

关 键 词：non-uniform beam physical parameter identification natural frequency transfer matrix method multibody system genetic algorithms 

分 类 号：O32[理学—一般力学与力学基础] O313.7[理学—力学]