摘要
传统工程水泥基复合材料(ECC)存在成本高、收缩大等问题,且缺乏关于加固用喷射型水泥基复合材料(SECC)循环冲击动力学特性的研究。基于此,采用霍普金森压杆对加固用SECC进行了压缩和劈裂两种方式下的循环冲击试验,系统分析了应力-应变曲线、变形和能量演化特征、疲劳损伤破坏特征,详细探究了各物理量的变化规律,并建立了力学特性预测模型。结果表明:循环压缩下,反射能转化率持续上升,而吸收能、透射能转化率持续下降;相比第1次冲击,最终破坏时吸收能转化率降低了63.94%。循环劈裂下,反射能转化率维持上升趋势,而透射能、吸收能转化率保持下降趋势;3次循环劈裂后,相比第1次冲击,最终破坏时吸收能转化率降低了0.72%;试件的变形损伤和能量损伤均随循环冲击次数的增加而增加,基于能量特征的损伤变量普遍高于变形特征下的损伤变量。两种循环冲击试验破坏时,能量损伤变量分别提高了913.19%和222.89%;SECC有助于为待加固层在冲击应力下提供所需要的柔性变形空间,也为动力能量释放提供了柔性缓冲空间。
The traditional engineered cementitious composites(ECC) have problems of high cost and large shrinkage,and there is a lack of research on cyclic impact dynamic characteristics of sprayed engineered cementitious composites(SECC) for reinforcement.Based on this,the split Hopkinson pressure bar was used to carry out cyclic impact test for SECC under compression and splitting.The stress-strain curve,deformation and energy evolution characteristics,fatigue damage and failure characteristics were systematically analyzed.The variation rule of each physical quantity was explored in detail,and the prediction model of mechanical properties was established.The result indicates that under cyclic compression,the conversion rate of reflection energy continues to increase,while the conversion rate of absorption energy and transmission energy continues to decrease.Compared with the first impact,the conversion rate of absorbed energy is reduced by 63.94% at the final destruction.Under the cyclic splitting,the conversion rate of reflection energy maintains upward trend,while the conversion rate of transmission energy and absorption energy maintains downward trend.After 3 cycles of splitting,compared with the first impact,the absorption energy conversion rate at the final failure is reduced by 0.72%.The deformation damage and energy damage of specimen increase with the increase of cyclic impacts.The damage variables based on energy characteristics are generally higher than those with deformation characteristics.When the two sorts of cyclic impact tests are damaged,the energy damage variables increase by 913.19% and 222.89% respectively.SECC helps to provide the required flexible deformation space for the reinforced layer under impact stress,and also provides flexible buffer space for dynamic energy release.
作者
韩辰悦
胡时
庞建勇
HAN Chen-yue;HU Shi;PANG Jian-yong(School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan,Anhui 232001,China;Zhejiang Provincial Engineering Research Center of Intelligent Urban Infrastructure,Hangzhou,Zhejiang 310015,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2024年第7期142-152,共11页
Journal of Highway and Transportation Research and Development
基金
中国博士后科学基金面上项目(2020M681974)
安徽省高等学校自然科学研究重点项目(KJ2020A0297)
城市基础设施智能化浙江省工程研究中心开放基金项目(IUI2023-YB-05)。
关键词
隧道工程
动力学特性
循环冲击
喷射型水泥基复合材料
疲劳损伤
tunnel engineering
dynamic characteristics
cyclic impact
sprayed engineered cementitious composites
fatigue damage
