Local damage detection using the two-dimensional gapped smoothing method
Local damage detection using the two-dimensional gapped smoothing method
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DOI：
10.1016/j.jsv.2003.10.058
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发表时间：
2005-01
影响因子：
4.7
通讯作者：
M. Yoon;D. Heider;J. Gillespie;C. Ratcliffe;R. Crane
中科院分区：
文献类型：
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作者：
M. Yoon;D. Heider;J. Gillespie;C. Ratcliffe;R. Crane
本文提出了一种定位结构刚度变异性的方法。对于某些类型的结构，这种可变性与制造缺陷和/或使用中损坏直接相关。与许多已发表的损伤检测方法不同，本文提出的方法仅使用从受损结构中获得的数据。在这里的分析中没有使用未损坏结构的基线数据和理论模型。该程序定位结构中刚度变化的区域。如果已知结构在未损伤状态下，相对于刚度是均匀的，则该程序将检测由早期损伤引起的不均匀区域。对于非均匀结构，需要一些结构细节的知识（例如，工程图纸或基线测试），以便区分损伤。该过程是先前发表的一维间隙平滑方法的二维推广，其中使用局部曲线拟合（即平滑）提取振动曲率形状的局部特征。为结构上的每个测试点生成一个可变性指数。变异性的增加是由于结构刚度特征或损伤。对指标进行统计处理，可以区分具有显著刚度变异性的区域。如果受损区域与总表面积相比足够小，它们的指数将是统计上的异常值。该程序既可以分析模态形状数据，也可以分析频率相关的操作位移形状数据。该方法通过板的有限元模型和复合材料板的实验进行了验证。最后，对某大型复合材料船体结构的数据进行了验证。在所有情况下，该程序都成功地定位了受损区域。
This paper presents a procedure for locating variability in structural stiffness. For some types of structure, this variability is directly related to manufacturing defects and/or in-service damage. Unlike many published damage detection methods, the procedure presented here uses only data obtained from the damaged structure. Baseline data and theoretical models of the undamaged structure are not used during the analysis presented here. The procedure locates regions in a structure where the stiffness varies. Providing it is known that the structure, in its undamaged state, is homogeneous with respect to stiffness, the procedure will detect the areas of inhomogeneity that are caused by the incipient damage. For non-homogeneous structures, some knowledge of the structural details (for example, engineering drawings or a baseline test) is required in order to discriminate damage. The procedure is a two-dimensional generalization of a previously published one-dimensional gapped smoothing method, whereby local features in vibration curvature shapes are extracted using a localized curve fit (i.e., smoothing). A variability index is generated for each test point on the structure. Increased variability is due either to structural stiffness features or damage. A statistical treatment of the indices enables discrimination of areas with significant stiffness variability. Providing the damaged areas are sufficiently small compared to the total surface area, their indices will be statistical outliers. The procedure can either analyze mode shape data, or frequency dependent operating displacement shape data. The procedure is demonstrated with a finite element model of a plate, and experiments on composite plates with deliberately induced multiple delaminations. Finally, the method is demonstrated on data taken from a large composite hull structure. In all cases the procedure successfully located the damaged regions.