混凝土受载试验全过程声发射特性研究与应用  

Study of Characteristics of Acoustic Emission during Entire Loading Tests of Concrete and Its Application

作　　者：赖于树[1,2] 熊燕[1,2] 程龙飞[3] 

机构地区：[1]重庆三峡学院电子与信息工程学院,重庆404000 [2]重庆三峡学院信号与信息处理重点实验室,重庆404000 [3]重庆三峡学院土木工程学院,重庆404000

出　　处：《建筑材料学报》2015年第3期380-386,共7页Journal of Building Materials

基　　金：重庆市基础与前沿研究计划项目(cstc2014jcyjA30006);重庆市教委科技项目(KJ1401022);重庆高校创新团队建设计划项目(KJTD201320)

摘　　要：利用微机控制力学试验机和SAEU2S数字声发射系统对混凝土试件进行了单轴受压声发射试验,研究了混凝土试件破裂全过程的声发射特征,重点探讨了频谱特征、能量变化、声发射事件计数率等与试件失稳破损过程各阶段的对应关系.试验表明混凝土试件的失稳破坏并不是瞬间完成的,而是内部显微裂纹扩展形成更大的宏观裂纹,并最终贯通导致破坏的过程.声发射事件伴随试件受力压密与弹性变形、塑性变形及裂纹贯通破损的全过程,在不同阶段具有显著不同特征.以此为判据,设计了混凝土工程稳定性声发射预警试验系统,验证表明该系统能够反映出混凝土工程失稳情况,及时准确发出预警信息.The acoustic emission（AE）test of a concrete specimen subjected to uniaxial compression was carried out by CNC mechanical testing machine and SAEU2 Sdigital acoustic emission system.The damage process in a concrete specimen was monitored by means of the propagating AE signal because of crack growth.The frequency spectrum character,energy change curve,AE counts,AE rate,and the relations between them and time were discussed in detail.The experiments show that the failure of concrete specimen is not instantaneous,but is such a transition from internal diffused microcracking to localised macrocracks and eventually to penetrating fracture.Acoustic emission can be detected in the whole process,whether that is emitted in the initial compaction and elastic deformation stage,or later in plastic deformation and penetrating fracture damage stage.In different stages the acoustic emission has significantly different characteristics.Based on this theory,a concrete structure stability acoustic emission warning system was designed.The results show that the system is able to correctly reflect the instability status of the concrete structure,and timely and accurately give warning information.

关 键 词：混凝土 声发射 信号处理 稳定性预警系统 

分 类 号：TU45[建筑科学—岩土工程] TH878[建筑科学—土工工程]