Measurement of strain distribution in bonded joints by fiber Bragg gratings
Measurement of strain distribution in bonded joints by fiber Bragg gratings
复制标题
用光纤布拉格光栅测量粘合接头的应变分布
DOI：
10.1117/12.316982
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
J. M. Menéndez
中科院分区：
文献类型：
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作者：
J. A. Guemes;S. Diaz;J. M. Menéndez
由于胶层尺寸小、应变场高度不均匀以及胶粘材料的非线性弹性行为，胶接处的应变分布可以通过有限元法来预测，但不能通过经典方法通过实验获得；只有莫尔干涉仪等非标准程序或 KGR 引伸计等特殊工件才能提供有关粘合剂行为的一些见解。由于尺寸小，确保了应变场的低扰动，并且它们具有测量沿传感器的应变和应变梯度的固有能力，光纤布拉格光栅为解决这个问题提供了一个很好的机会，并且它是可能受益于这些新型传感器的情况的一个很好的例子。光纤布拉格光栅可以放置在粘合层内或界面处，或者嵌入在粘附物处（如果这些是由复合材料制成的话）。测试可以在不同的温度下进行，将粘合剂特性从脆性改变为假塑性，而不会产生额外的困难。接头加载时，通过分析反射光脉冲的畸变光谱得到应变场；执行此操作的算法已经发布。与理论结果进行了比较，并证明了这些传感器对于该应用和类似应用的有效性和实用性。
Due to the small dimensions of the adhesive layer, the high non-uniformity of the strain field and the non linear elastic behavior of the adhesive material, the strain distribution at an adhesive joint can be predicted by FEM, but can not be experimentally obtained with classical approaches; only non standard procedures like Moire interferometry, or special artifacts like KGR extensometers may afford some insights on the behavior of the adhesive. Due to their small size, ensuring low perturbation of the strain field, and their innate ability to measure strain and strain gradient along the sensor, fiber Bragg gratings offer a good opportunity to solve this problem, and it is a good example of situations that may benefit from these new sensors. Fiber Bragg gratings may be placed or at the interface, within the adhesive layer, or embedded at the adherents, if these were made of composite material. Tests may be run at different temperatures, changing the adhesive characteristics from brittle to pseudoplastic without additional difficulties. When loading the joint, the strain field is obtained by analyzing the distorted spectrum of the reflected light pulse; the algorithm for doing it has already been published. A comparison with theoretical results is done, and the validity and utility of these sensors for this and similar applications is demonstrated.