Many existing damage identification or quantification methods can be employed only if the internal and external mass changes are negligible when tested at two different states of a structure. This paper presents a new Modal Kinetic Energy (MKE)-based method to detect and quantify damage using modal properties of structures, which can be employed even in situations when mass change is not more than a certain extent. A new damage sensitivity parameter has been developed using measured modal characteristics of baseline structure. The MKE change (MKEC) concept is then employed to locate damage and to estimate relative perturbation at each element. The relative damage extent vector is estimated by searching the best correlation between the analytical and experimental MKEC vectors with the help of genetic algorithm optimization tool. The extent of damage is calculated after computing damage scaling coefficient using measured eigenvalue change vector. A numerical study is carried out on a simply supported single span beam to confirm its performance under various test conditions. The robustness of the proposed MKE method and the significance of mass variation in the damage detection approach are evaluated by comparing the damage quantification results with a traditional approach. Finally, the proposed damage detection method is applied on a two-span simply supported beam for single and multiple damage scenarios by extracting the modal properties experimentally. The results revealed that the proposed approach is capable of detecting and estimating single and multiple damages with reasonable accuracy even in moderate noise contaminated and mass change environments.

中文翻译：

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使用模态动能变化的基于相关性的损伤识别和量化

只有当在结构的两种不同状态下进行测试时，内部和外部质量变化可以忽略不计时，才能使用许多现有的损伤识别或量化方法。本文提出了一种基于模态动能 (MKE) 的新方法，该方法利用结构的模态特性检测和量化损伤，即使在质量变化不超过一定程度的情况下也可以使用该方法。使用基线结构的测量模态特性开发了一种新的损伤敏感性参数。然后使用 MKE 变化 (MKEC) 概念来定位损坏并估计每个元素的相对扰动。在遗传算法优化工具的帮助下，通过搜索分析和实验MKEC向量之间的最佳相关性来估计相对损伤程度向量。使用测量的特征值变化向量计算损伤比例系数后计算损伤程度。对简支单跨梁进行了数值研究，以确认其在各种测试条件下的性能。通过将损伤量化结果与传统方法进行比较，评估了所提出的 MKE 方法的稳健性和损伤检测方法中质量变化的重要性。最后，通过实验提取模态属性，将所提出的损伤检测方法应用于单跨和多损伤场景的两跨简支梁。结果表明，即使在中度噪声污染和质量变化环境中，所提出的方法也能够以合理的精度检测和估计单个和多个损伤。