基于声发射特征参数的玻纤格栅复合梁阻裂机理表征  

Characterization of Crack Resistance Mechanism of Fiberglass Geogrid Reinforced Composite Beam Based on Acoustic Emission Characteristic Parameters

作　　者：周圣雄 王威娜[1,2] 秦煜[1,3] 刘佳亮 ZHOU Shengxiong;WANG Weina;QIN Yu;LIU Jialiang(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;National and Local Joint Engineering Laboratory of Traffic Civil Engineering Materials,Chongqing Jiaotong University,Chongqing 400074,China;CREEC(Chongqing)Survey,Design and Research Co.,Ltd,Chongqing 400023,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074 [2]重庆交通大学交通土建工程材料国家地方联合工程实验室,重庆400074 [3]中铁二院重庆勘察设计研究院有限责任公司,重庆400023

出　　处：《材料导报》2021年第22期22033-22038,共6页Materials Reports

基　　金：国家自然科学基金(52078091,51978114);重庆市自然科学基金(cstc2020jcyj-msxmX0624)。

摘　　要：为揭示玻纤格栅对复合梁弯曲开裂行为的阻裂机理,本工作开展基于声发射(AE)技术的带缝水泥混凝土板加铺沥青层结构的三点弯曲试验,通过声发射特征参数对比分析有无玻纤格栅夹层两类复合梁的弯曲断裂过程,探究试件损坏过程中AE参数演化特征,通过RA值和AF值分析了复合梁的断裂模式,并结合分形理论研究玻纤格栅对复合梁弯曲断裂特征的影响。研究结果表明:声发射特征参数可有效识别玻纤格栅的作用时期;玻纤格栅在荷载峰值后逐渐开始承受弯拉荷载,延缓了宏观裂缝的扩展,对复合梁的峰后持荷能力有明显提升作用,但承力时期滞后于沥青加铺对弯曲破坏荷载没有影响;玻纤格栅夹层的存在降低了复合梁拉伸破坏趋势,提高了复合梁弯曲破坏过程中的有序性,使复合梁中的微裂缝从产生、发展以及汇集成宏观裂缝至最终弯曲破坏的变化成为更加有序且渐近的过程,从而使该过程有明显的分形特征。In order to reveal the crack resistance mechanism of the fiberglass geogrid on the bending cracking behavior of the composite beam,an experimental of three-point bending of the composite beam with cement overlay asphalt layer was applied.Study the bending and fracture process of the two types of composite beams with or without fiberglass geogrid interlayer through acoustic emission(AE)characteristic parameters,and explore the evolution characteristics of acoustic emission parameters in the process of specimen damage.The fracture of composite beam was analyzed by calculating the values of RA and AF.The effect of fiberglass geogrid on the bending and fracture characteristics of composite beams was studied through fractal theory.The research results show that the AE characteristic parameters can effectively identify the pe-riod of action of the fiberglass geogrid.The fiberglass geogrid gradually bears the bending and tensile load and delays the propagation of macro cracks,and it can obviously improve the ability of maintain load after peak of the composite beam.The load-bearing period of the fiberglass geogrid lags behind the asphalt overlay,which has no effect on the bending failure load.The fiberglass geogrid improves the orderliness of the bending process of the composite beam,making micro-cracks’change from the generation,development,and the integration of macro-cracks to the final bending failure become a more orderly and asymptotic process of the composite beam,which makes it with obvious fractal feature.

关 键 词：复合梁 声发射 加铺 三点弯曲 玻纤格栅 断裂功 分形 

分 类 号：U416.2[交通运输工程—道路与铁道工程]