固定载荷下光纤光栅应变传感阵列检测裂缝悬臂梁损伤的研究

介绍了光纤光栅分布式传感原理,推导了悬臂梁受载荷时的应变计算公式,以金属悬臂梁为研究对象,以光纤光栅应变传感阵列为传感工具,实验研究了固定载荷下裂缝悬臂梁的光纤光栅检测的新方法.金属悬臂梁上光纤光栅应变传感阵列粘贴的位置和预制裂纹的位置由有限元模拟确定,固定载荷的加载是在金属悬臂梁的自由端悬挂标准砝码.记录金属悬臂梁在无损伤、一条裂缝、两条裂缝和三条裂缝的光纤光栅应变传感阵列检测到的实验数据,以无损伤的实验数据为初始数据,分别与有损伤的实验数据进行比较,得到悬臂梁在各个损伤情况下的应变变化量,根据应变变化量的不同,确定出悬臂梁上损伤的位置.

Study on Fiber Bragg Grating Strain Sensing Array Measuring Damage of Crack Cantilever Beam under the Fixed Load

The distributed sensing principles of fiber Bragg grating were introduced, and the strain calculation of cantilever beam bearing load was derived. Taking metal cantilever beam as the research object, and fiber Bragg grating strain sensing array as the sensing tool, the new detection method of the crack cantilever beam under fixed load by fiber Bragg grating was studied experimentally. The pasting positions of fiber Bragg grating strain sensing array and the position of the prefabricated crack on metal cantilever beam were confirmed by finite element modeling, and the fixed load is to hang standard weight on the free end of the metal cantilever beam. The experimental data were recorded when the metal cantilever beam has no damage, one crack, two cracks and three cracks. Taking the no damaged experimental data as the original data, comparing with the damaged data respectively, the strain variation of cantilever beam under different damage status was obtained. According to the difference of the strain variation, the damage position of the cantilever beam can be confirmed.