A structural damage identification technique hinged on the combination of orthogonal empirical mode decomposition and modal analysis is proposed. The output-only technique is based on the comparison between pre- and post-damage free structural vibrations signals. The latter are either kinematic (displacements, velocities or accelerations) or deformation measures (strains or curvatures). The response data are decomposed by means of the orthogonal empirical mode decomposition to derive a finite set of orthogonal intrinsic mode functions; the latter are used as a multi-frequency and data-driven basis to build pseudo-modal shapes. A new damage index, the so-called pseudo-mode index, is introduced to compare the response obtained for the two states of the structural system and detect potential damages. The performance of the devised index in detecting a localised damage is shown through numerical and experimental tests on two structural models, namely a 4-degrees-of-freedom system and a two-hinged parabolic arch.

中文翻译：

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基于正交经验模态分解的伪模态结构损伤指标

提出了一种基于正交经验模态分解和模态分析相结合的结构损伤识别技术。仅输出技术基于损坏前和损坏后自由结构振动信号之间的比较。后者是运动学（位移、速度或加速度）或变形测量（应变或曲率）。响应数据通过正交经验模态分解得到一组有限的正交固有模态函数；后者被用作多频率和数据驱动的基础来构建伪模态形状。引入了一种新的损伤指数，即所谓的伪模指数，用于比较结构系统两种状态下获得的响应并检测潜在的损伤。