基于声发射和分形的钢筋混凝土受剪梁损伤  

Damage of reinforced concrete shear beams based on acoustic emission and fractal

作　　者：于江[1] 赵志浩[1] 秦拥军[1] YU Jiang;ZHAO Zhi-hao;QIN Yong-jun(School of Civil Engineering and Architecture,Xinjiang University,Urumqi 830047,China)

机构地区：[1]新疆大学建筑工程学院,乌鲁木齐830047

出　　处：《吉林大学学报（工学版）》2021年第2期620-630,共11页Journal of Jilin University:Engineering and Technology Edition

基　　金：国家自然科学基金项目(51668060)。

摘　　要：通过5根不同剪跨比和不同配箍率的钢筋混凝土梁受剪破坏试验,运用声发射检测技术和分形理论对混凝土梁细观和宏观损伤演化过程进行研究。根据梁受剪破坏过程中产生的声发射信号的能量和振铃计数等参数以及裂纹分形特征,定量分析了混凝土梁受剪损伤演化过程。试验结果表明:声发射振铃计数和能量随损伤程度呈三阶段变化,累计振铃计数和累计能量以及裂纹分形维数随荷载水平的增大而增大,增速随剪跨比的增大而增大,随配箍率的增大而减小,证明声发射参数可作为损伤程度的评价指标。通过建立累计声发射能量和荷载水平的相关关系,推导出了受剪梁损伤演化模型,并将损伤程度与梁表面裂纹分形维数建立相关关系,得到了混凝土梁受剪损伤评估方程,可为实际工程中受剪梁损伤评估提供参考。Through the shear failure test of five reinforced concrete beams with different shear span ratio and different hoop ratio,the damage evolution process of concrete beams was studied by using acoustic emission detection technology and fractal theory. Based on the parameters of acoustic emission signal energy,ringing count and crack fractal characteristics,the evolution of shear damage of concrete beams is quantitatively analyzed. Test results show that the acoustic emission ringing counts and energy with the damage degree are divided into three stages. The accumulate ringing count,energy and the fractal dimension of crack increase with load level. The growth rate of the crack increases with the shear span ratio,while decreases with increasing stirrup ratio,proving that the acoustic emission parameters can be used as a damage degree evaluation index. By establishing the correlation between the cumulative acoustic emission events and the load level,the damage evolution model of the shear beam is derived,and the correlation between the damage degree and the fractal dimension of the beam surface crack is established.

关 键 词：结构工程 混凝土梁 损伤 声发射 分形 剪跨比 配箍率 

分 类 号：TU375.1[建筑科学—结构工程]