基于静力响应面的混凝土梁桥有限元模型修正

Finite element model updating based on static-load response surface method for concrete beam bridge

研究基于中心复合设计的静力响应面法在桥梁有限元模型修正中的具体应用.桥梁结构的静力测试受干扰小、过程明确,具有较高的精度和稳定性.以静载试验挠度为响应,进行中心复合设计,拟合能模拟响应与因子间的曲面函数关系的二阶响应面模型.通过调整坐标轴样本点的取值使中心复合设计具有正交性.以方差分析定量判定回归方程和因子的显著性,并通过剔除不显著因子提高响应面模型的精度.对三跨连续梁抗弯刚度的修正结果表明:基于静力测试的二阶响应面模型,对梁桥有限元模型的修正精度能满足工程要求.

This paper presents the application of central composite design based on static-load response surface method in finite element model updating for bridges.Static load tests of bridge structures possess many special characteristics,such as little external interference,high accuracy and perfect stability,etc.Based on central composite design,with deflection as response,a second-order response surface model is drafted,to fit the function of the factorial-response curved surface.By adjusting the values of coordinate axes sample points,central composite design can be orthogonal.Analysis of covariance is used to assess the significance of the equations and regression coefficients,therefore factors that are not significant will be deleted to increases the accuracy of RSM model.A tested 3-span continuous girder bridge is used to verify the proposed method.It has been observed that static-load second-order response surface method gives certain accuracy in finite element model updating for bridges.