以高层钢框架预应力索支撑结构为例，研究了应用AR 模型进行脉动风模拟时，模型的2 个关键参数——时间步长、时域点数的取值对模拟结果的影响。在讨论基于AR 模型的脉动风模拟方法的基础上，利用有限元软件Sap2000 建立结构模型，利用Matlab 编制AR 算法程序，分别选用不同的时间步长、时域点数对结构进行脉动风速时程分析，将生成的脉动风速功率谱曲线与目标谱进行对比，根据曲线吻合情况确定参数的合理取值范围。结果表明，时间步长的取值对AR 模型模拟结果有较大影响，其最优值域为0.10~0.18 s，超出这一范围均会导致功率谱曲线与目标谱偏离，降低模拟精度；时域点数对AR 模型模拟精度的影响较小，可根据工程需要选择时域点数。
Two critical parameters of the AR model are studied in the simulation of the fluctuating wind-time step and time points, focusing on the influence of the two parameters on the simulation of a high-rise steel frame with prestressed cable supports. The simulation of the fluctuating wind is based on the AR model, the finite element software Sap2000 is used to build the structural model, a mathematical software is used to program the AR model. Various values of the two parameters are selected, the modal analysis and the time history analysis of the structure are made. The ensemble power spectrum curve and the ensemble cross power spectrum curve are compared with the target power spectrum curve, and the reasonable value can be selected through the match of two curves. It is indicated that the value of the time step has a great effect on the accuracy of the simulation, and the suitable value should be around 0.10-0.18 s, if the value exceeds the range, the ensemble power spectrum can not match the target power spectrum and the accuracy of the simulation can not be ensured. The number of time points have little impact on the simulation.
[1] Iannuzzi A, Spinelli P. Artificial wind generation and structural response[J]. Journal of Structural Engineering, ASCE, 1987, 113(12): 2382-2398.
[2] Owen J S. The application of auto regressive time series modeling for the time frequency analysis of civil engineering structures[J]. Engineering Structures, 2001, 23: 521-536.
[3] 舒新玲, 周岱, 王泳芳. 风荷载测试与模拟技术的回顾及展望[J]. 振动 与冲击, 2002, 21(3): 6-10. Shu Xinling, Zhou Dai, Wang Yongfang. The retrospect and prospect of wind load test and simulation technology[J]. Journal of Vibration and Shock, 2002, 21(3): 6-10.
[4] 舒新玲, 周岱. 风速时程AR模型及其快速实现[J]. 空间结构, 2003, 9 (4): 27-32. Shu Xinling, Zhou Dai. AR model of wind speed time series and its rapid implementation[J]. Spatial Structures, 2003, 9(4): 27-32.
[5] 胡雪莲, 李正良, 晏致涛. 大跨度桥梁结构风荷载模拟研究[J]. 重庆建 筑大学学报, 2005, 27(3): 63-67. Hu Xuelian, Li Zhengliang, Yan Zhitao. Simulation of wind loading for large-span bridge strucres[J]. Journal of Chongqing Jianzhu University, 2005, 27(3): 63-67.
[6] 袁波, 应惠清, 徐佳炜. 基于线性滤波法的脉动风速模拟及其 MATLAB程序的实现[J]. 结构工程师, 2007, 23(4): 55-61. Yuan Bo, Ying Huiqing, Xu Jiawei. Simulation of turbulent wind velocity based on linear filter method and matlab program realization[J]. Structural Engineers, 2007, 23(4): 55-61.
[7] 张冬兵, 梁枢果, 韩银全, 等. 高层建筑风场的脉动风速时程模拟[J]. 兰州理工大学学报, 2008, 34(3): 127-130. Zhang Dongbing, Liang Shuguo, Han Yinquan, et al. Simulation of time history of turbulent wind speed in wind field around high-rises[J]. Journal of Lanzhou University of Technology, 2008, 34(3): 127-130.
[8] 张希黔, 葛勇, 严春风, 等. 脉动风场模拟技术的研究与进展[J]. 地震 工程与工程振动, 2008, 28(6): 206-212. Zhang Xiqian, Ge Yong, Yan Chunfeng, et al. Advances in research of simulation technology of fluctuation wind loading[J]. Journal of Earthquake Engineer and Engineer Vibration, 2008, 28(6): 206-212.
[9] 陈俊儒, 吕西林. 上海中心大厦脉动风荷载模拟研究[J]. 力学季刊, 2010, 31(1): 92-100. Chen Junru, Lü Xilin. Simulation of fluctuating wind load of shanghai center tower[J]. Chinese Quarterly of Mechanics, 2010, 31(1): 92-100.
[10] 万春风, 黄磊, 汪江, 等. 脉动风作用下塔架结构的风振响应分析[J]. 科技导报, 2010, 30(1): 39-43. Wan Chunfeng, Huang Lei, Wang Jiang, et al. Wind-induced response of a tower structure under fluctuating wind load[J]. Science & Technology Review, 2010, 30(1): 39-43.
[11] 唐柏鉴, 顾盛. 预应力巨型支撑—钢框架结构侧移模式研究[J]. 建筑 科学, 2010, 26(9): 57-61. Tang Baijian, Gu Sheng. Study on lateral resistance performance of prestressed-mega-brace-steel frame structure[J]. Building Science, 2010, 26(9): 57-61.
[12] Davenport A G. Wind effects on civil engineering structures[J]. Canadian Journal of Civil Engineering, 1984, 11(4): 1025-1026.
[13] Kareem A, Kijewski T. 7th US national conference on wind engineering: A summary of papers[J]. Journal of Wind Engineering and Industrial Aerodynamics, 1996, 62(1): 81-129.
[14] Grigoriu M. On the spectral representation method in simulation[J]. Probabilistic Engineering Mechanics, 1993(8): 75-90.
[15] Naganuma T, Deodatis G, Shinozuka M. ARMA modal for two dimensional process[J]. Journal of Engineering Mechanics, ASCE, 1987, 113(2): 234-251.
[16] Samaras E, Shinozuka M, Tsurui A. ARMA representation of random process[J]. American Society of Civil Engineers, 1985, 111(3): 449-461.
[17] Shinozuka M. Simulation of multivariate and multidimensional random proecess[J]. Journal of the Acoustical Society of America, 1971, 49(3): 357-367.
