多电极CFRP-OFBG传感筋的力学性能和传感特性试验研究

Study on mechanical properties and sensing properties of multi-electrode CFRP-OFBG sensing bars

为探索碳纤维增强复合材料筋(CFRP筋)的线性度、重复性、灵敏度等传感特性,采用CFRP筋表面开槽后嵌入光纤布拉格光栅传感器(OFBG)的封装方法,通过静力拉伸试验和等幅循环拉伸试验分析对比了由OFBG所测应变与CFRP筋的电阻变化率间的对应关系,并实现了对CFRP筋传感特性的校准与标定。本文试验采用的OFBG封装方法对CFRP筋力学性能的不利影响很小,且未改变OFBG的应变传感特性;CFRP-OFBG传感筋在0~5000με应变区间内,所测CFRP筋的电阻变化率与OFBG应变满足线性关系,CFRP筋的应变传感灵敏度系数为26.71,线性可决系数大于0.97;在等幅循环拉伸试验中,CFRP筋的电阻变化率与OFBG所测应变的变化趋势一一对应。OFBG的标定试验表明,CFRP筋可独立实现高可靠性、高灵敏度、可重复的应变自感知功能。

In order to explore the linearity,repeatability and sensitivity of Carbon Fiber Reinforced Plastic bars(CFRP bars),embedding Optical Fiber Bragg Grating(OFBG)on the surface of CFRP bars,through static tensile test and constant amplitude cyclic tensile test,the relationship between the strain measured by OFBG and the resistance change rate of CFRP bars was analyzed and compared.And the sensing characteristics of CFRP bars are calibrated.The results show that the fiber packaging method has little effect on the mechanical properties of CFRP bars and does not change the strain sensing characteristics of OFBG.In the 0~5000μεstrain range of CFRP-OFBG bars,the resistance change rate of CFRP bars is linear with the OFBG strain.The strain sensing sensitivity coefficient of CFRP bars is 26.71,and the linear determinable coefficient is greater than 0.97.And the changing trend between resistance change rate of CFRP bars and strain measured by OFBG is consistent in the constant amplitude cyclic tensile test.In a word,CFRP bars can achieve high reliability,repeatability and high sensitivity of strain self-sensing performance.