In this study, a modal-based structural damage identification method is proposed and applied to a portal beam structure as a case study. A two-stage evaluation method, involving the combination of a residual force vector method and an eigensensitivity method, is proposed to determine the locations of damaged elements in a finite element model. The physical model variables of these elements are then updated using an optimization updating method that detects damage severity. The optimization algorithm to update the model is solved using a sequential quadratic programming method. The severity of the elemental damage is indicated by the final updated physical model variables of the finite element analysis model. The effectiveness of the two-stage evaluation and optimization update methods is verified via comparison of the reference and updated physical model variables through the case study. It is determined that the structural damage detection method with two-stage evaluation and optimization updating developed in this study could be applied for the monitoring and early warning of structural damage.

在这项研究中，提出了一种基于模态的结构损伤识别方法，并将其应用于案例研究。提出了一种将残余力矢量法和特征敏感性法结合起来的两阶段评估方法，以确定有限元模型中受损单元的位置。然后，使用检测损坏严重程度的优化更新方法来更新这些元素的物理模型变量。使用顺序二次规划方法求解更新模型的优化算法。元素损伤的严重程度由有限元分析模型的最终更新物理模型变量指示。通过案例研究，通过比较参考模型和更新后的物理模型变量，验证了两阶段评估和优化更新方法的有效性。经确定，本研究开发的具有两阶段评价和优化更新的结构损伤检测方法可用于结构损伤的监测和预警。