Using Ambient Vibrations to Detect Loosening of a Composite-to-Metal Bolted Joint in the Presence of Strong Temperature Fluctuations
Using Ambient Vibrations to Detect Loosening of a Composite-to-Metal Bolted Joint in the Presence of Strong Temperature Fluctuations
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使用环境振动检测存在强烈温度波动时复合金属螺栓接头的松动
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
E. Eisner
中科院分区：
文献类型：
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作者：
J. Nichols;S. Trickey;M. Seaver;S. Motley;E. Eisner
提出了一种检测结构损伤非线性的方法。该方法首先涉及创建符合适当的零假设（无损坏）的替代数据集。第二步是将从原始数据中提取的一些非线性“特征“与从替代数据中提取的那些特征进行比较。统计学上的显著差异表明支持备择假设（损伤）的证据。使用这种方法，我们展示了如何松散的连接可以检测到使用环境“波”强迫，符合皮尔逊-莫斯科维茨分布，作为源的激励。我们还证明了这种技术的操作能力，没有记录的基线数据集，并在存在广泛变化的温度。在这种情况下，结构是一个厚的，复合梁螺栓连接到钢框架。使用光学应变传感系统收集数据。在这个实验中，我们能够可靠地检测到螺栓松动的存在。
We present an approach for detecting damage-induced nonlinearities in structures. The method first involves the creation of surrogate data sets conforming to an appropriate null hypothesis (no damage). The second step is to then compare some nonlinear "feature " extracted from the original data to those extracted from the surrogates. Statistically significant differences suggest evidence in favor of the alternative hypothesis, damage. Using this approach we show how loose connections can be detected using ambient "wave" forcing, conforming to the Pierson-Moskowitz distribution, as the source of excitation. We also demonstrate the ability of this technique to operate without a recorded baseline data set and in the presence of widely varying temperatures. The structure in this case is a thick, composite beam bolted to a steel frame. Data are collected using an optical strain sensing system. For this experiment we are able to reliably detect the presence of a loosened bolt.