Deng Aimin, Cao Maosen, Lu Qitian, Xu Wei
Department of Engineering Mechanics, Hohai University, Nanjing 210098, China.
Jiangsu Province Wind Power Structural Engineering Research Center, Hohai University, Nanjing 210098, China.
Sensors (Basel). 2021 Sep 15;21(18):6171. doi: 10.3390/s21186171.
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.
识别梁式构件中的裂纹对于确保结构安全具有重要意义。在依赖振型的方法中，横向伪力（TPF）的概念已被充分证明可用于识别各向同性材料梁中的单条和多条裂纹；然而，TPF概念与其在复合材料层合梁中的应用之间存在明显差距。为了填补这一差距，提出了一种基于动态平衡摄动的增强型TPF方法，用于识别复合材料层合梁中的多条裂纹。本研究从横向运动方程出发，推导了用于识别复合材料层合梁中多条裂纹的TPF。该方法的性能通过有限元方法进行了数值验证。该方法的适用性在具有三条裂纹的碳纤维增强聚合物层合梁上进行了实验验证，其振型通过使用扫描激光测振仪的非接触式振动测量获得。特别地，采用一种统计方式使该方法在缺乏材料和结构信息的情况下能够适用于实际场景；此外，采用一种积分方案使该方法即使在振型节点附近也能够识别裂纹。
