Q235A钢在不同加载速率下的声发射特性分析  

Acoustic Emission Analysis of Q235A Steel Under Different Loading Rates

作　　者：杨果岳[1] 杜冕 刘秀[1] YANG Guoyue;DU Mian;LIU Xiu(College of Civil Engineering and Mechanics,Xiangtan Universily,Xiangtan 411105.China)

机构地区：[1]湘潭大学土木工程与力学学院,湖南湘潭411105

出　　处：《建筑钢结构进展》2018年第5期98-103,108,共7页Progress in Steel Building Structures

摘　　要：为了分析加载速率增大过程中材料屈服强度提高的声发射特性,对工程结构常用钢Q235A的拉伸破坏过程进行声发射检测。通过预加载得到了Q235A钢材拉伸试验的声发射门槛确定值,采取铅芯折断试验来确定声发射技术的各时间参数:峰值鉴别时间(PDT)、撞击鉴别时间(HDT)和撞击闭锁时间(HLT)。结果表明:试验得到的声发射特征指标(幅值、能量计数、撞击计数等)对不同加载速率下材料塑性屈服阶段的强度变化有较好的信号表达,且材料拉伸过程的声信号参数指标与其力学效应能够准确的吻合。由此可知声发射检测技术为进一步描述钢材损伤的发展过程和材料结构的变化情况提供了可靠依据,对于更合理地把握钢材在不同加载速率条件下的裂纹发育和构件破坏提供了技术参考。In order to analyze the acoustic emission characteristics of the material yield strength during the process of increasing loading rate,we use acoustic emission to test the tensile failure process of common steel Q235A in building structures.The threshold value of Q235A steel tensile test is determined by pre-loading,and the lead core break test is adopted to determine the time parameters of acoustic emission technology which are peak discrimination time（PDT）,hit discrimination time（HDT）and hit lock time（HLT）.The result shows the acoustic emission parameters such as amplitude,energy counting and hit counting are preferable parameters to express the strength of the plastic yield stage under different loading rates,and the expression of acoustic signal parameters in the process of the material stretching can be exactly consistent with the mechanical effect.Therefore,it can be known that the acoustic emission testing technology provides a reliable basis for the further describing in the development process of steel damage and the change of material structure.Besides,it provides a technical reference for making a better catch to the crack growth and component failure under different loading rates.

关 键 词：加载速率 拉伸试验 声发射 参数选取 特性分析 铅芯折断试验 

分 类 号：TU391[建筑科学—结构工程]