Identification of cracks in beam-type components is significant to ensure the safety of structures. Among the approaches relying on mode shapes, the concept of transverse pseudo-force (TPF) has been well proved for single and multiple crack identification in beams made of isotropic materials; however, there is a noticeable gap between the concept of TPF and its applications in composite laminated beams. To fill this gap, an enhanced TPF approach that relies on perturbation to dynamic equilibrium is proposed for the identification of multiple cracks in composite laminated beams. Starting from the transverse equation of motion, this study formulates the TPF in a composite laminated beam for the identification of multiple cracks. The capability of the approach is numerically verified using the FE method. The applicability of the approach is experimentally validated on a carbon fiber-reinforced polymer laminated beam with three cracks, the mode shapes of which are acquired through non-contact vibration measurement using a scanning laser vibrometer. In particular, a statistic manner is utilized to enable the approach to be feasible to real scenarios in the absence of material and structural information; besides, an integrating scheme is utilized to enable the approach to be capable of identifying cracks even in the vicinity of nodes of mode shapes.

中文翻译：

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使用动态平衡扰动识别复合材料层合梁中的多重裂纹

梁式构件裂纹的识别对于确保结构安全具有重要意义。在依赖模态振型的方法中，横向伪力 (TPF) 的概念已被很好地证明用于各向同性材料制成的梁中的单裂纹和多裂纹识别；然而，TPF 的概念与其在复合层压梁中的应用之间存在明显的差距。为了填补这一空白，提出了一种依赖于动态平衡扰动的增强型 TPF 方法，用于识别复合层压梁中的多个裂纹。本研究从横向运动方程出发，制定了复合层合梁中的 TPF，用于识别多个裂缝。该方法的能力使用有限元方法进行了数值验证。该方法的适用性在具有三个裂纹的碳纤维增强聚合物层压梁上进行了实验验证，其模式形状是通过使用扫描激光测振仪的非接触式振动测量获得的。特别是利用统计的方式，使该方法在缺乏材料和结构信息的情况下对真实场景是可行的；此外，利用积分方案使该方法能够识别甚至在模态振型节点附近的裂纹。采用统计方式，使该方法在缺乏材料和结构信息的情况下对真实场景可行；此外，利用积分方案使该方法能够识别甚至在模态振型节点附近的裂纹。采用统计方式，使该方法在缺乏材料和结构信息的情况下对真实场景可行；此外，利用积分方案使该方法能够识别甚至在模态振型节点附近的裂纹。