桥梁结构劣化与损伤过程的多尺度分析方法及其应用

研究桥梁结构多尺度模拟和分析方法对于发展重大桥梁结构损伤检测与状态评估方法以确保其安全运营是至关重要的.本文综述和总结了作者及其课题组多年来在桥梁结构劣化与损伤过程分析领域的研究工作.包括:系统地提出了针对大型桥梁结构损伤劣化过程分析需求的结构多尺度问题,研究证实了结构损伤与劣化过程分析可以通过结构一致多尺度模拟和时空多尺度分析来实现;提出了针对大型桥梁结构多尺度模型的多因素、多目标同步模型修正技术,指出多尺度模型修正必须对各分析目标敏感的多种因素同步优化,同时交叉验证修正后模型对该级修正目标和对其它模拟目标的复现与预测能力.提出了基于结构一致多尺度模拟和结构健康监测信息进行结构劣化分析的方法并应用于两个重大桥梁工程结构的疲劳损伤分析与评估.最后,指出在此领域中还要很多问题亟待解决,尤其是如何模拟损伤从材料与结构中的细观层次的缺陷演化发展到结构局部乃至整体失效的过程,建立结构损伤演化与失效过程的跨尺度分析理论与方法.

MULTI-SCALE MODELING AND ANALYSES ON STRUCTURAL DETERIORATION AND DAMAGE IN LONG-SPAN BRIDGES AND ITS APPLICATION

It is significant to develop the method of multi-scale modeling and damage analyses on structural deteriorating in order to maintain safe and reliable service of long-span bridges. This paper summarize recent works on multi-scale modeling and analyses of long-span bridges for the popurse of evaluating structural deterorating and damage by authors and their research group. The main outcomes include that, the methodology and strategy for concurrent finite element modeling of long-span bridges at the different scale levels have been developed for the purposes of analyses on structural deteriorating. The model updating techniques with concurrent multi-objective and multi-factor optimization technique were developed for concurrently updating the multi-scale model of the bridge. The proposed procedures of multi-scale model modeling, updating and verification were applied to the model verification of Runyang bridges and Tsing Ma Bridge as an actual engineering practice of the proposed procedures. The method of numerically simulating structural deteriorating and damage involution in multiple multiple temporal and spatial scales was developed based on the developed multi-scale model and applied to the analyses on long-span bridges under service loading. At last, it is suggested that, there are some key issues to be studied in the region, such as, how to explain the damage evolution from defects in meso-scale to local fracture and bridge failure, and to develop the theory and analyses method for a trans-scale damage evolution in long-span bridges.