含双空孔缺陷试件三点弯曲冲击试验  

Three Point Bending Impact Test of Specimen with Double-hole Defects

作　　者：何松林 范嘉宾 严振湘 尹芝足[3] 肖成龙 HE Song-lin;FAN Jia-bin;YAN Zhen-xiang;YIN Zhi-zu;XIAO Cheng-long(School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China;China Railway Construction Group Co.,Ltd.,Beijing 100040,China;Shougang Mining Company,Qian an 064400,China;State Key Lab of Explosion Science and Technology,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京科技大学土木与资源工程学院,北京100083 [2]中铁建设集团有限公司,北京100040 [3]首钢矿业公司,迁安064400 [4]北京理工大学爆炸科学与技术国家重点实验室,北京100081

出　　处：《科学技术与工程》2023年第25期10658-10663,共6页Science Technology and Engineering

基　　金：国家自然科学基金重点项目(51934001)。

摘　　要：为了研究双孔缺陷对运动裂纹的作用机制,采用数字激光动态焦散线系统对含双空孔缺陷的有机玻璃板三点弯曲梁进行冲击断裂实验,分析研究了双空孔缺陷下裂纹扩展的路径、尖端动态强度因子、扩展速度以及焦散斑的变化规律。结果表明:空孔缺陷会吸引周围运动的裂纹,导致裂纹运动轨迹发生变化;含双空孔缺陷试件起裂难度显著增加,起裂的临界应力强度因子增加了24.29%;运动裂纹在接近双空孔缺陷时,双空孔缺陷对裂纹的扩展有明显的抑制作用,裂纹通过双空孔缺陷中心后,双空孔缺陷对裂纹的扩展有促进作用。In order to study the action mechanism of double-hole defects on moving cracks,a digital laser dynamic caustics system was used to test the impact fracture of a three-point flexural beam of a plexiglass plate with double-hole defects.The crack propagation path,tip dynamic strength factor,propagation velocity and the change law of caustic speckle under double-hole defects were analyzed and studied.The results show that the cracks moving around are attracted by the empty hole defects,and the trajectory of the cracks is changed.The crack initiation difficulty of specimens with double-cavity defects increases significantly,and the critical stress intensity factor of crack initiation increases by 24.29%.When the moving crack is close to the double-empty hole defect,the double-empty hole defect has an obvious inhibition effect on the crack growth,and when the crack passes through the double-empty hole defect center,the double-empty hole defect has a promotion effect on the crack growth.

关 键 词：焦散线 空孔缺陷 冲击荷载 动态应力强度因子 

分 类 号：O347.3[理学—固体力学]