基于DIC与AE技术的湿筛混凝土轴拉试验研究
Axial Tensile Test of Wet-Screened Concrete Based on Digital Image Correlation and Acoustic Emission
石振祥 1陈徐东 1张忠诚 1郭玉柱 1赵威中 2孙成飞2
作者信息
- 1. 河海大学土木与交通学院,南京 210098
- 2. 中建三局集团有限公司华东分公司,南京 210098
- 折叠
摘要
为探究不同加载速率(1×10-6、5×10-6、25×10-6 s-1)下湿筛混凝土的单轴拉伸试验裂缝扩展规律,结合声发射(AE)技术和数字图像相关(DIC)技术对湿筛混凝土试件进行实时监测,从而获得不同加载速率下试件位移-荷载曲线、声发射信号及裂缝扩展位置.结果表明:在轴向拉伸过程中,加载速率越快,试件损伤指数逐渐向线性发展;同时,混凝土试件的断裂主要是粗骨料与胶凝材料的胶结面破坏,并伴有少量粗骨料被拉断,骨料断裂位置与声发射能量信号反映匹配度较高;随着加载速率增加,试件主裂缝位移占轴向位移的比例显著增加,说明加载速率越快,试件内部应变集中越严重,从而加重试件破坏程度.研究成果对于湿筛混凝土断裂性能的研究具有一定的参考价值.
Abstract
To investigate the crack development behavior of wet-screened concrete under uniaxial tensile test at vari-ous loading rates(1×10-6、5×10-6、25×10-6 s-1),a combination of acoustic emission(AE)and digital image cor-relation(DIC)was utilized to monitor the wet-screened concrete specimens in real time.Displacement-load curves,acoustic emission signals and crack location under different loading rates were obtained.The findings revealed that in the axial tensile process,the cumulative energy within the specimen increased with increasing loading rate,and the damage index of the specimen developed linearly.Meanwhile,the fracture of the specimens was mostly due to the failure of the surface between coarse aggregate and cementitious material,accompanied by the destruction of coarse aggregate.The fracture location of the aggregate highly corresponded with the AE energy signal.As the load-ing rate increased,the proportion of the primary crack displacement to the axial displacement of the specimen in-creased significantly,indicating a considerable strain concentration within the specimen.
关键词
湿筛混凝土/单轴拉伸/数字图像相关/声发射/损伤识别Key words
wet screened concrete/uniaxial tension/digital image correlation/acoustic emission/damage identifi-cation引用本文复制引用
基金项目
国家重点研发计划项目(2021YFB2600200)
国家自然科学基金面上项目(51979090)
国家重点实验室开放基金项目(2019CEM002)
出版年
2024
国家科技期刊平台
NSTL
维普
万方数据