拉/压状态下混凝土声发射信号参数特征试验研究  

Study on characteristics of parameters of acoustic emission signals from concrete in tensile or compressive states

作　　者：刘洋甫 刘思孟[1] 陈坤 陈强[1] 蒲于立 谈俊杰 LIU Yangfu;LIU Simeng;CHEN Kun;CHEN Qiang;PU Yuli;TAN Junjie(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学土木工程学院,重庆400074

出　　处：《混凝土》2023年第2期10-14,共5页Concrete

基　　金：国家重点研发计划“低交通影响下既有城市桥梁快速维修加固关键技术和应急装置”(2017YFC0806007)。

摘　　要：声发射信号特征与力学状态的内在联系,是推动声发射技术发展和完善的重要理论基础,但是目前相关的工作尚待加强。从理论角度分析了声发射现象、损伤与应变/应力之间的内在联系,开展了混凝土梁的加载试验,利用实测数据深入探讨了这些物理量的关联。试验数据显示,以振铃计数为代表的计数类参数和以幅值为代表的能量类参数与应力状态演化强度相关,而信号频率与拉/压应力类型之间的关联不明显;混凝土受拉区产生的信号,其振铃计数和幅值随着荷载值增长呈现波动上升态势,参数值通常较受压产生的信号更大;当试件进入到带裂缝阶段的后期,受压区信号参数才表现出与荷载增长一致的趋势。沿梁高方向上,声发射信号的振铃计数和幅值的分布与应变之间存在显著的相关性;在梁截面的中性轴处,上述两个参数在分布形态和数值方面都出现了明显的跳跃。上述结果表明,声发射信号的参数具有刻画混凝土结构内部力学状态的潜力。The relationship between acoustic emission(AE)signal features and mechanical parameters is an important physical basis to develop and improve acoustic emission-based technology,however,relevant work needs to reinforce.The relations among AE phenomenon,damage and strain/stress were analyzed theoretically,and an experiment on a concrete beam was carried out.The experimental data showed that counts-like parameters(such as counts)and the energy-based parameters represented by amplitude correlated strongly with the stress,while the correlation between signal frequency and stress types was not significant.For signals from concrete in the tensile state,parameters counts and amplitude demonstrated the same trend as load values,and magnitudes of these features were usually relatively larger than those of the signals form compression zones.Along the specimen′s depth direction,the distributions of counts and amplitude correlated significantly with the strain.Near the neutral axis of the specimen cross section,the distributions and values of these two parameters showed a huge jump.These results revealed that AE signal features had the great potential to characterise internal mechanical states of concrete structures.

关 键 词：混凝土 应力状态 声发射 振铃计数 幅值 频率 

分 类 号：TU528.01[建筑科学—建筑技术科学]