基于响应面理论的高拱坝模型修正损伤识别研究

本文以二滩拱坝为工程背景,利用基于响应面理论的模型修正方法进行了结构损伤识别分析。分析过程中,将坝体合理分成若干子区域,以子区域的弹性模量折减来指示损伤,根据坝面节点灵敏度及响应面精度选择合理的测点。建立合适的响应面模型来反映坝体的动力特性与损伤变量之间的非线性关系,最后采用遗传算法进行优化计算。响应面方法的引入避免了损伤识别过程中反复调用有限元计算程序,提高了计算效率;同时提出基于坝体多次测量数据下的损伤识别方法,以提高算法的抗噪性。数值计算结果表明,本文提出的方法能有效应用于高拱坝损伤识别。

Model updating method for damage identification of high dam based on response surface theory

This paper describes an analysis on identification of structure damages in high arch dams using the model modification of response surface method with application to a case study of the Ertan dam. This method uses measurements at the gauge points that were carefully located considering sensitivity and accuracy of the response surface, and divides the dam body into sub-regions of different reduction in elastic modulus so that a different damage parameter can be used for the reduction in each sub-region. Then, relationships of the dynamics at the gauge points versus the corresponding damage parameters are represented by certain functions charactering the response surface, and therefore the damage features can be obtained via optimization using a genetic algorithm. This response surface method avoids repeated calls for FEM calculation in damage identification and thus lowers computational cost. To improve noise immunity, a technique of using multiple measurements is suggested in this paper. Numerical results show that our method can effectively identify damages in high arch dams.