桥梁预应力混凝土徐变系数曲线拟合方法研究  

Study on Curve Fitting Method for Creep Coefficient of Prestressed Concrete Bridges

作　　者：刘龙 苏伟 王雨权 廖立坚 傅安民 杨智慧 LIU Long;SU Wei;WANG Yuquan;LIAO Lijian;FU Anmin;YANG Zhihui(Civil Engineering Design Research Institute,China Railway Design Corporation,Tianjin 300308,China)

机构地区：[1]中国铁路设计集团有限公司土建院,天津300308

出　　处：《铁道标准设计》2024年第10期105-111,共7页Railway Standard Design

基　　金：中国铁路设计集团有限公司科技开发课题(2022B03406026)。

摘　　要：有限元分析中徐变效应精确分析的关键在于徐变系数的指数形式能否准确还原徐变系数曲线。为研究一种高精度的任意徐变系数曲线的拟合方法以实现有限元徐变分析精确求解,本文剖析了该问题的本质,并提出一种优化算法,即利用模拟退火法寻找全局最优解的能力搜寻初解,再通过Levenberg-Marquardt法精确求解,并以2个算例对该方法进行验证。研究结果表明:(1)本文提出的徐变系数曲线拟合方法能对徐变系数曲线进行精确拟合;(2)算例结果显示本文提供的算法在拟合公路规范和铁路规范的徐变系数曲线时,相关系数R均在0.9999以上,拟合精度高,通用性强;(3)本文提供的算法架构简单、层次清晰,可借助常用编程语言方便地进行编译,对有限元程序徐变分析模块的开发或混凝土徐变规律的相关科学研究具有借鉴意义。Accurate analysis of creep effects in finite element analysis depends on whether the exponential form of the creep coefficient can accurately reproduce the creep coefficient curve.This paper aims to develop a high-precision fitting method for arbitrary creep coefficient curves to achieve accurate finite element creep analysis.The core issue was examined,and an optimization algorithm was proposed.First,the simulated annealing algorithm was used to search for the global optimal solution,followed by the application of the Levenberg-Marquardt algorithm for precise calculations.Two examples were employed to verify the method.The results showed that:(1)The proposed creep coefficient curve fitting method could accurately fit the creep coefficient curve.(2)The case studies showed that the algorithm achieved a correlation coefficient(R)above 0.9999 when fitting the creep coefficient curves according to highway and railway standards,indicating high fitting accuracy and strong general applicability.(3)The proposed algorithm featured a simple structure and clear hierarchy,allowing for easy implementation using common programming languages.This method provides valuable insights for the development of finite element program creep analysis modules or related scientific research on concrete creep behavior.

关 键 词：预应力混凝土桥 混凝土 徐变系数 曲线拟合 理论研究 模拟退火法 LEVENBERG-MARQUARDT算法 

分 类 号：U24[交通运输工程—道路与铁道工程] U441[建筑科学—桥梁与隧道工程] U448.33