基于FDM-DEM的礁灰岩混凝土动态冲击损伤及破裂特征研究  

Dynamic impact damage and rupture characteristics of reef limestone concrete based on FDM-DEM coupling method

作　　者：邓运辰 余亚桥 范然 胡桐 姚方阳 李帅豪 罗忆[1,2] DENG Yunchen;YU Yaqiao;FAN Ran;HU Tong;YAO Fangyang;LI Shuaihao;LUO Yi(School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan 430070,China;Sanya Science and Education Innovation Park,Wuhan University of Technology,Sanya 572024,China)

机构地区：[1]武汉理工大学土木工程与建筑学院,湖北武汉430070 [2]武汉理工大学三亚科教创新园,海南三亚572024

出　　处：《水利水电快报》2024年第12期103-112,共10页Express Water Resources & Hydropower Information

基　　金：海南省自然科学基金创新研究团队项目(521CXTD444);国家大学生创新创业训练计划项目(202310497082)。

摘　　要：为分析礁灰岩混凝土动态冲击损伤及破裂特征,配置C30礁灰岩混凝土,通过FDM-DEM耦合的方法建立礁灰岩混凝土的SHPB模型,模拟分析了不同冲击荷载下礁灰岩混凝土动态响应的应变率效应,并利用PFC软件编写的声发射监测系统对礁灰岩混凝土动态损伤及细观破裂演化过程进行分析。结果表明:随着应变率的增大,动态应力峰值增长速率先快速增长然后趋于稳定,动态应力峰值增加了25.51%;当应变率增加至67.8 s^(-1)时,礁灰岩混凝土试样由Ⅰ型破坏模式转变到Ⅱ型破坏模式,动态应力卸载产生的回弹现象消失,动态应力应变曲线呈开口型,且开口程度随应变率升高不断扩大;动态强度放大系数DIF随着应变率的增加呈非线性增大,但增速逐渐变缓,DIF与应变率具有指数关系(DIF=1.45ε^(·0.15));声发射事件数与试样内部应力具有正相关性,随着应力的增长,试样内部裂纹增长速率较快,当应力降低时,内部裂纹增长趋近平稳。研究成果可为类似工程提供参考。To analyze the dynamic impact damage and fracture characteristics of reef limestone concrete,C30 reef limestone concrete was prepared.The SHPB model of reef limestone concrete was constructed by the FDM-DEM coupling method.The strain rate effect of dynamic response of reef limestone concrete under different impact loads was simulated and analyzed.The acoustic emission monitoring system compiled by PFC software was used to analyze the dynamic damage and meso-fracture evolution process of reef limestone concrete.The results show that as the strain rate increases,the growth rate of dynamic stress peak increases rapidly and then tends to remain stable,and the dynamic stress peak increases by 25.51%.When the strain rate increases to 67.8 s^(-1),the reef limestone concrete specimen changes from type I failure mode to type Ⅱ failure mode,and the rebound phenomenon caused by dynamic stress unloading disappears.The dynamic stress strain curve is open,and the opening degree increases with increasing strain rate.The dynamic strength amplification factor DIF increases non-linearly with increasing strain rate,but the growth rate gradually slows down.There is an exponential relationship between DIF and strain rate(DIF=1.45ε^(·0.15)).The number of acoustic emission events is positively correlated with the internal stress of the sample.As the stress increases,the growth rate of internal cracks in the sample is faster.When the stress decreases,the growth of internal cracks tends to remain stable.The research results can provide a reference for similar projects.

关 键 词：礁灰岩混凝土 动态力学特性 FDM-DEM耦合 SHPB冲击实验 裂纹演化 

分 类 号：TU528[建筑科学—建筑技术科学]