基于DIC技术的UHPC箱型拱试验全过程研究

Research on the w hole process of UHPC box arch test based on DIC technology

为研究超高性能混凝土(UHPC)拱在静载试验下的受力性能及开裂破坏的全过程,基于数字图像相关(DIC)技术,采用数字散斑图像的匹配追踪分析方法,分析了L/4截面单点加载情况下UHPC拱表面从加载到破坏的相对变形分布和变形规律。结果表明:通过分析试件表面广义主应变场的时变规律,可准确描述UHPC拱裂缝出现及开展的全过程;随着荷载的增大,控制截面的挠度相应变化,传统测量方法测得的挠度与DIC技术所得具有较高的一致性;使用DIC技术可以准确判断UHPC拱表面初始开裂的时间、位置以及裂纹的走向。研究方法与结论对于准确表述UHPC结构的受力状态及裂缝开展过程具有重要意义,也为混凝土结构的安全监测与力学性能检测研究提供了新途径。

In order to study the mechanical property and the whole process of cracking failure of the ultra-high performance concrete(UHPC)arch under static load test,based on the digital image correlation(DIC)technique,the matching deformation analysis method of the digital speckle image was used to analyze the relative deformation distribution and deformation law of the UHPC arch surface from loading to failure under the 1/4 section single point loading.The results show by analyzing the time-varying law of the generalized main strain field on the specimen surface,the occurrence and development of UHPC arch fracture can be accurately described.As the load increases,the deflection of the control section changes accordingly,and the deflection measured by the traditional measurement method is highly consistent with that obtained by DIC technology.DIC technology can be used to accurately determine the time,location and crack trend of the UHPC arch surface.The research methods and conclusions are of great significance to accurately describe the stress state and crack development process of UHPC structure,and also provide a new approach for the safety monitoring and mechanical property detection of concrete structures.