沙漠砂聚苯乙烯混凝土峰前、峰后应力松弛试验研究  

Experimental Study on Pre-peak and Post-peak Stress Relaxation of Desert Sand Polystyrene Concrete

作　　者：牛晟 康亚明[1,2] 陈静波 刘鹏 NIU Cheng;KANG Yaming;CHEN Jingbo;LIU Peng(Chemical Science and Engineering College,State Ethnic Affairs Commission,North Minzu University,Yinchuan 750021,China;Key Laboratory of Chemical Engineering and Technology,State Ethnic Affairs Commission,North Minzu University,Yinchuan 750021,China;Ningxia Qiangong Prestressing Technology Engineering Co.,Ltd.,Yinchuan 750200,China;Ningxia Hengcheng Construction Engineering Consulting Co.,Ltd.,Yinchuan 750001,China)

机构地区：[1]北方民族大学化学与化学工程学院,宁夏银川750021 [2]北方民族大学国家民委化工技术基础重点实验室,宁夏银川750021 [3]宁夏千弓预应力技术工程有限公司,宁夏银川750200 [4]宁夏恒诚建设工程咨询有限公司,宁夏银川750001

出　　处：《济南大学学报（自然科学版）》2020年第2期118-123,共6页Journal of University of Jinan(Science and Technology)

基　　金：国家自然科学基金项目(51569001)

摘　　要：采用分级加载的方式,对密度为900 kg/m 3的沙漠砂聚苯乙烯(EPS)混凝土进行单轴峰前、峰后应力松弛试验,根据试验结果系统研究沙漠砂EPS混凝土的峰前、峰后应力松弛特性;对广义Kelvin模型引入损伤变量,建立沙漠砂EPS混凝土应力松弛损伤模型,并结合Levenberg-Marquardt优化算法对参数进行辨识。结果表明:沙漠砂EPS混凝土试块峰前、峰后应力松弛曲线形态相似且均由衰减松弛、稳定松弛2个部分组成,衰减松弛部分峰前相较于峰后更为明显,但从稳定松弛角度看,峰后表现更为突出;峰前试块的应力松弛量随应变的增大而增大,剩余应力比随应变的增大而减小,峰后试块的应力松弛量随应变的增大呈现递减趋势,剩余应力比随应变的增大呈现增大趋势;相较于广义Kelvin模型,广义Kelvin损伤模型可以更好地描述沙漠砂EPS混凝土的峰前、峰后应力松弛特性。By the method of grading loading,the uniaxial pre-peak and post-peak stress relaxation experimentof desert sand polystyrene(EPS)concrete with density of 900 kg/m 3 was carried out.According to the results of the experiment,the pre-peak and post-peak stress relaxation properties of the desert sand EPS concrete were researched systematically.A stress relaxation damage model of desert sand EPS concrete was established by introducing damage variables into the generalized Kelvin model,and the parameters were identified by Levenberg-Marquardt optimization algorithm.The results show that the pre-peak and post-peak stress relaxation curves of desert sand EPS concrete are similar in shape and composed of attenuation relaxation and stability relaxation.The attenuation relaxation is more obvious in pre-peak than that in post-peak,but from the perspective of stability relaxation,the post-peak performance is more prominent.The stress relaxation of pre-peak test block increases with the increase of strain,and the residual stress ratio decreases with the increase of strain.The stress relaxation of post-peak test block decreases with the increase of strain,and the residual stress ratio increases with the increase of strain.Compared with the generalized Kelvin model,the generalized Kelvin damage model can better describe the pre-peak and post-peak stress relaxation characteristics of desert sand EPS concrete.

关 键 词：分级加载 沙漠砂聚苯乙烯混凝土 应力松弛 广义Kelvin模型 

分 类 号：TQ172[化学工程—水泥工业] TU528.79[化学工程—硅酸盐工业]