结构损伤一致多尺度模拟和分析方法

Concurrent multi-scale modeling of structures and damage analyses

以一个重要的大跨桥梁为工程背景,基于非线性有限元分析软件ABAQUS,研究了大跨结构以损伤分析和状态评估为目标的结构多尺度模拟中的一系列关键理论和技术问题,包括多尺度建模方法和策略、基于子结构方法和基于多点约束衔接方法的多尺度建模过程,结构一致多尺度模型的修正和验证,以及应用多尺度模型进行结构损伤分析的方法与策略.研究结果表明,应用所提出的大跨结构一致多尺度建模方法和策略,能够有效地建立适用于实际大跨桥梁结构损伤分析的多尺度有限元模型,满足不同尺度下结构特性分析和局部损伤演化过程仿真计算的需要.而基于多尺度模型进行的局部疲劳损伤累积的仿真分析结果表明,发生于局部焊接细节的疲劳损伤与结构的局部应力响应之间有较大的耦合作用,在结构的多尺度损伤分析过程中应予考虑才能得到比较准确的寿命评估结果.

The methodology and strategy for concurrent multi-scale modeling of large structures such as long span bridges were studied in order to perform the multi-scale numerical analysis on structural dynamic response and local damage. The multi-scale FE（ finite element） modeling was first studied by using substructure method and the multi-point constraints. A multi-scale model of the Tsing Ma Bridge （TMB） was then developed by using the design drawings and the proposed strategy on the basis of the software ABAQUS and the developed programs via the user interface. The model updating and verification were carried out based on the online data from the structural health monitoring system installed on the TMB. The procedure for damage analysis using the developed model was proposed, in which locally deteriorating process at welded details of interconnects is able to account for the major effect of the damage and nonlinear influence on structural response. The calculated result shows that damage features can be successfully performed via multi-scale modeling and analysis; and fatigue damage accumulation on the weld details shows significantly local effect. The fatigue life obtained from the fully coupled calculation on stress and damage is shorter than that from the un- couple computation, which suggests that the significant interaction between the damage and the structural response should be considered in the structural damage analyses using the multi-scale numerical analysis.