一种新的时域动态载荷识别方法
doi: 10.3969/j.issn.0258-2724.2012.06.010
A New Time-Domain Method for Force Identification
-
摘要: 为了准确地识别未知载荷和降低测量噪声对识别结果的影响,基于动态规划方法和Bellman最优化原理,提出了新的时域动态载荷识别方法.从系统的状态空间方程出发,利用最小二乘法建立了系统响应的实际测量值与识别值之间的目标函数,同时引入Newmark积分,得到了基于系统位移、速度和加速度响应的系统离散运动方程;将动态规划方法和Bellman最优化原理应用于目标函数的最小化,推导了动态优化载荷识别公式.通过数值算例对文中方法进行了验证,结果表明:该方法对动态载荷识别适应性强,在测量响应含有10%噪声干扰下,误差均低于25%.Abstract: In order to identify unknown load accurately and reduce the influence of measurement noise on identification results, a new time-domain method for dynamic load identification was proposed based on dynamic programming and Bellman optimization principle. First, the objective function between measured and identified system responses was established using the state-space formulation and the least square error method. Then, discrete equations of motion based on the system displacement, velocity, and acceleration responses were obtained by Newmark integration method. Finally, the dynamic programming method and Bellman optimization principle were used for minimization of the objective function to estimate the excitation forces, and identification formulations of optimal dynamic load were deduced. In addition, the numerical example was provided to verify the proposed mathematical model. The results show that the proposed method has a strong adaptability in dynamic load identification; under 10% noise disturbance, the error of measured response is always less than 25%.
-
WILLIAMS D, JONES R P N. Dynamic loads in aero planes under given impulsive loads with particular reference to landing and gust loads on a large flying boat[M]. : H.M. Stationery Office, 1948: 2215-2221. BRIGGS J C, TSE M.K. Impact force identification using extracted modal parameters and pattern matching[J]. Int. J. Impact Eng., 1992, 12(3): 361-372. YANG Y B, YAU J D. Vehicle bridge interaction element for dynamic analysis[J]. J. Struct. Eng., 1997, 123(11): 1512-1518. GIANSAMETE N, JONES R, CALAPODAS N J. Determination of in-flight helicopter loads[J]. Journal of the American Helicopter Society, 1982, 27(3): 58-64. KARLSSON S E S. Identification of external structural loads from measured harmonic responses[J]. Journal of Sound and Vibration, 1996, 196(1): 59-74. 许峰,陈怀海,鲍明. 动载荷识别的广义域模态模型及其精度分析研究[J]. 计算力学学报,2003,20(2): 218-222. XU Feng, CHEN Huaihai, BAO Ming. Study on the general domain based modal-model of force identification and its accuracy analysis[J]. Chinese Journal of Computational Mechanics, 2003, 20(2):218-222. 付春雨,单德山,李乔. 基于车致振动响应的铁路桥梁损伤位置识别[J]. 西南交通大学学报, 2011,46(5) : 719-725. FU Chunyu, SHAN Deshan, LI Qiao. Damage location identification of railway bridge based on vibration response caused by vehicles[J]. Journal of Southwest Jiaotong University, 2011, 46(5): 719-725. 单德山,李乔. 基于车致振动的桥梁损伤识别[J]. 西南交通大学学报,2009,44(1): 60-65. SHAN Deshan, LI Qiao. Damage detection of bridge structures based on moving vehicle caused vibration [J]. Journal of Southwest Jiaotong University, 2009, 44(1): 60-65. HUANG C H. An inverse non-linear force vibration problem of estimating the external forces in a damped system with time-dependent system parameters[J]. J. Sound Vib., 2001, 242(5): 749-765. 张运良,林皋,王永学,等. 一种改进的动态载荷时域识别方法[J]. 计算力学学报,2004,21(2): 209-215. ZHANG Yunliang, LIN Gao, WANG Yongxue, et al. An improved method of dynamic load identification in time domain[J]. Chinese Journal of Computational Mechanics, 2004, 21(2): 209-215. 李辉,丁桦. 一种基于比例反馈控制原理的动载荷时域反演方法[J]. 计算力学学报,2008,25(5): 602-609. LI Hui, DING Hua. A dynamic load identification method in time domain based on proportional feedback control principle[J]. Chinese Journal of Computational Mechanics, 2008, 25(5): 602-609. LIANG Yanehun, ZHOU Chunguang, WANG Zaishen. Identification of restoring forces in nonlinear vibration systems based on neural networks[J]. Journal of Sound and Vibration, 1997, 206(1): 103-105. INOUE H, KISHIMOTO K, SHIBUYA T. Experimentalwavelet analysis of flexural waves in beams[J]. Experimental Mechanics, 1996, 36(3): 212-217. LIN J H, GUO X L, ZHI H, et al. Computer simulation of structural random loading identification[J]. Computers and Structures, 2001, 79(4): 375-387. TRUJILLO D M, BUSBY H R. Practical inverse analysis in engineering[M]. Boca Raton: CRC Press LLC, 1997: 35-110. BELLMAN R. Dynamic programming[M]. Princeton: Princeton University Press, 1957: 45-120.
点击查看大图
计量
- 文章访问数: 1173
- HTML全文浏览量: 64
- PDF下载量: 388
- 被引次数: 0