共轭斜量法在BP2模式Dirichlet级数参数辨识中的应用  

Application of Conjugate Gradient Method to Parameter Identification of Dirichlet Series of BP2 Model

作　　者：黄娟[1] 周建春[1] 

机构地区：[1]华南理工大学亚热带建筑科学国家重点实验室

出　　处：《华南理工大学学报（自然科学版）》2009年第3期127-131,共5页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(50378040)

摘　　要：研究了一种大型结构混凝土徐变函数指数形式表达式参数辨识与拟合方法.选用混凝土徐变国际标准BP2模式,构建最普遍的退化核Dirichlet级数形式作为基函数,针对拟合过程中实际变量多于方程未知变量的情况,应用最小二乘法原理将矛盾方程转化为相应的法方程,引入共轭斜量法求解法方程.在此基础上编制的程序,可将BP2模式的Dirichlet级数形式的所有参数辨识出来.拟合公式和原公式结果吻合良好,相对误差在±3%以内.文中给出的BP2模式Dirichlet级数形式的拟合公式,可用于大型结构长期徐变效应的跟踪分析,为服役结构的状态评定提供依据.This paper investigates the parameter identification and fitting methods for large-scale structures to predict the concrete creep in an exponential form. In the investigation, first, the international standard BP2 model of concrete creep is employed to construct a common degenerate-kernel Dirichlet series as the basis function. Next, in view of the fact that the actual parameters are more than the unknown variables in the fitting process, the least square method is used to transform the inconsistent equation group into a normal one. Then, the normal equation group is solved by means of the conjugate gradient method. Finally, based on the presented techniques, program is worked out to identify the parameters of Dirichlet series of BP2 model. It is found that the fitted results accord well with the original ones, the relative error being less than ± 3 %. The recommended Dirichlet series of BP2 model is suitable for the tracking and analysis of long-term creep behavior of large-scale structures. Also, it provides a reference for the performance evaluation of existing structures.

关 键 词：徐变函数 BP2模式 参数辨识 DIRICHLET级数 共轭斜量法 

分 类 号：U448.35[建筑科学—桥梁与隧道工程]