吴俊^1,2, 杜修力¹, 李亮¹
AuthorsHTML:吴俊^1,2, 杜修力¹, 李亮¹
AuthorsListE:Wu Jun^1,2, Du Xiuli ², Li Liang ¹
AuthorsHTMLE:Wu Jun^1,2, Du Xiuli ², Li Liang ¹
Unit:1. 北京工业大学城市与工程安全减灾教育部重点实验室，北京 100124；2. 上海工程技术大学城市轨道交通学院，上海 201620
Unit_EngLish:1．Key Laboratory of Urban Security and Disaster Engineering, Ministry of Education, Beijing University of Technology, Beijing 100124, China
2．School of Urban Railway Transportation, Shanghai University of Engineering Science, Shanghai 201620, China
Abstract_Chinese:为研究沥青混凝土材料在强动载条件下的动态性能, 采用液压伺服试验机和霍普金森压杆(SHPB)对沥青混凝土进行了不同应变率下的压缩试验, 得出了中高应变率下沥青混凝土材料的动力增长系数(DIF)和材料的动态应力-应变关系曲线．运用考虑应变率效应的弹塑性损伤模型对沥青混凝土的SHPB试验进行模拟, 并通过室内试验确定本构模型中的关键参数, 如强度面曲线和损伤因子等．结果表明：采用液压伺服仪和SHPB可以有效地得出沥青混凝土在中高应变率下的动力增长系数, 沥青混凝土抗压强度随着应变率的提高而增加; 采用室内试验可以快速准确地确定弹塑性本构模型中的相关参数, 用以表述沥青混凝土的应力-应变关系; 当数值模拟中采用SHPB试验中获取的动力增长系数时, 将导致惯性效应的重复, 故对沥青混凝土材料进行高应变率下数值模拟时, 应不考虑SHPB试验中由于环向惯性效应所引起的那部分动力增长系数, 即需要对SHPB试验所得的动力增长系数做修正．
Abstract_English:To explore the dynamic properties of asphalt concrete under severe dynamic loading，the apparatus of servo hydraulic machine and split Hopkinson pressure bar (SHPB) were employed to conduct the dynamic compression test for asphalt concrete material. The dynamic increase factor (DIF) and dynamic stress-strain curve were then obtained for asphalt concrete under middle to high strain rates. At same time，the advanced elasto-plastic damaged model strain rate effect was used to simulate the dynamic behavior of asphalt concrete in SHPB test. The key parameters for the selected material models，i.e. parameters of strength surfaces and the damage factor，were calibrated and quantified through laboratory tests. The results obtained are stated as follows: the apparatus of hydraulic servo machine and SHPB can be effectively used to obtain the DIF curve for asphalt concrete under middle to high strain rates. The compressive strength of asphalt concrete increased with the enhancement of strain rates. Laboratory tests can be used to quickly determine the key parameters of advanced elasto-plastic damaged model in order to represent the dynamic stress strain behavior of asphalt concrete. It was also found that the compressive DIFs of asphalt concrete obtained from SHPB test should consider contribution from two factors，one was the moisture effect at lower stain rates which was related to the first branch of DIFs curve obtained from SHPB test，and another was the lateral inertial confinement effect at higher stain rates which was related to the second branch of DIFs curve obtained from SHPB test. However，for the numerical model of asphalt concrete under dynamic loading，adopting the DIFs curve obtained from SHPB test would duplicate the inertial effects. Hence，when the numerical simulation of asphalt concrete under high strain rate loading was conducted，the second phase of compressive DIF obtained from SHPB test should not be considered，that is，the compressive DIFs obtained from SHPB test should be modified.
Keyword_Chinese:沥青混凝土; 动力增长系数; 霍普金森压杆试验; 损伤模型
Keywords_English:asphalt concrete; dynamic increase factor; SHPB test; damaged model

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