混凝土类材料在霍普金森杆实验中的受力状态研究
发布时间：2019-06-12 17:59
【摘要】：混凝土作为最常用的工程材料之一，研究其动态压缩力学性能，对于基础建设和结构防护都有着重要的现实意义，当前对混凝土材料在较高应变率下的力学特性的研究还较少。本文简要回顾混凝土材料动态压缩力学性能的研究进展,并对动态增强因子（DIF）经验公式存在的问题进行论述。指出，由于对加载方式影响试件受力状态的认识不足，前人对DIF的研究只局限于试件处于一维应力状态，并未考虑其多轴应力状态状态下的情况，应将受力状态对材料DIF的影响计入综合考量。使用LS-Dyna中72号模型（mat concrete damage rel3，又叫KC模型）对霍普金森杆（SHPB）压缩试验进行数值模拟，得到SHPB试件中的应力与应变状态。采用该混凝土模型分别对考虑摩擦和不考虑摩擦的不同长径比和不同直径的SHPB试件进行了数值模拟。具体工作如下： （1）选用KC模型，，设计不同长径比和不同直径的试件。通过改变试件与压杆接触界面的摩擦系数，分析试件的受力状态。结果表明界面摩擦系数以及混凝土试件长径比和直径对其在高应变率下的受力状态有较大的影响。 （2）对KC模型中抗压缩破坏系数b1、拉伸破坏系数b2、三轴拉伸破坏系数b3的影响进行了参数分析，以期调整得到合适的参数值，为以后的实验研究提供参考。结果表明参数b1对应变率以及应力应变关系影响很大，而其他两个参数对应变率以及应力应变关系基本没有影响。 结论对脆性材料SHPB试件的设计及SHPB实验结果的解释有一定的指导意义。
[Abstract]:As one of the most commonly used engineering materials, the study of dynamic compression mechanical properties of concrete is of great practical significance for infrastructure construction and structural protection. At present, there is little research on the mechanical properties of concrete materials under high strain rate. In this paper, the research progress of dynamic compression mechanical properties of concrete materials is briefly reviewed, and the problems existing in the empirical formula of dynamic reinforcement factor (DIF) are discussed. It is pointed out that due to the lack of understanding of the influence of loading mode on the stress state of the specimen, the previous research on DIF is limited to the one-dimensional stress state of the specimen, and does not consider the multi-axial stress state, and the influence of the stress state on the material DIF should be taken into account. The (SHPB) compression test of Hopkinson rod is simulated by using 72 model (mat concrete damage rel3, in LS-Dyna, also known as KC model, and the stress and strain states in SHPB specimen are obtained. The concrete model is used to simulate SHPB specimens with different aspect ratio and different diameter considering friction and not considering friction respectively. The specific work is as follows: (1) KC model is selected to design specimens with different aspect ratio and different diameter. By changing the friction coefficient of the contact interface between the specimen and the compression bar, the stress state of the specimen is analyzed. The results show that the interfacial friction coefficient, the aspect ratio and diameter of concrete specimens have great influence on the stress state of concrete specimens at high strain rate. (2) the effects of compression failure coefficient b1, tensile failure coefficient b2 and triaxial tensile failure coefficient b3 in KC model are analyzed in order to adjust the appropriate parameters and provide reference for future experimental research. The results show that parameter b1 has great influence on strain rate and stress-strain relationship, while the other two parameters have little effect on strain rate and stress-strain relationship. Conclusion it has certain guiding significance for the design of brittle material SHPB specimen and the explanation of SHPB experimental results.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528
本文编号：2498198
[Abstract]:As one of the most commonly used engineering materials, the study of dynamic compression mechanical properties of concrete is of great practical significance for infrastructure construction and structural protection. At present, there is little research on the mechanical properties of concrete materials under high strain rate. In this paper, the research progress of dynamic compression mechanical properties of concrete materials is briefly reviewed, and the problems existing in the empirical formula of dynamic reinforcement factor (DIF) are discussed. It is pointed out that due to the lack of understanding of the influence of loading mode on the stress state of the specimen, the previous research on DIF is limited to the one-dimensional stress state of the specimen, and does not consider the multi-axial stress state, and the influence of the stress state on the material DIF should be taken into account. The (SHPB) compression test of Hopkinson rod is simulated by using 72 model (mat concrete damage rel3, in LS-Dyna, also known as KC model, and the stress and strain states in SHPB specimen are obtained. The concrete model is used to simulate SHPB specimens with different aspect ratio and different diameter considering friction and not considering friction respectively. The specific work is as follows: (1) KC model is selected to design specimens with different aspect ratio and different diameter. By changing the friction coefficient of the contact interface between the specimen and the compression bar, the stress state of the specimen is analyzed. The results show that the interfacial friction coefficient, the aspect ratio and diameter of concrete specimens have great influence on the stress state of concrete specimens at high strain rate. (2) the effects of compression failure coefficient b1, tensile failure coefficient b2 and triaxial tensile failure coefficient b3 in KC model are analyzed in order to adjust the appropriate parameters and provide reference for future experimental research. The results show that parameter b1 has great influence on strain rate and stress-strain relationship, while the other two parameters have little effect on strain rate and stress-strain relationship. Conclusion it has certain guiding significance for the design of brittle material SHPB specimen and the explanation of SHPB experimental results.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528
【参考文献】
相关期刊论文 前10条
1 高文学,杨军,黄风雷;强冲击载荷下岩石本构关系研究[J];北京理工大学学报;2000年02期
2 武海军;黄风雷;付跃升;张庆明;马爱娥;;钢筋混凝土中爆炸破坏效应数值模拟分析[J];北京理工大学学报;2007年03期
3 施绍裘,陈江瑛,李大红,王礼立;水泥砂浆石在准一维应变下的动态力学性能研究[J];爆炸与冲击;2000年04期
4 宋力,胡时胜;SHPB数据处理中的二波法与三波法[J];爆炸与冲击;2005年04期
5 薛志刚;胡时胜;;水泥砂浆在主动围压下的动态力学性能[J];爆炸与冲击;2008年06期
6 薛志刚;胡时胜;;水泥砂浆在围压下的动态力学性能[J];工程力学;2008年12期
7 蒋国平;陶为俊;刘洁;;气体炮冲击高强混凝土试验的数值模拟[J];广州大学学报(自然科学版);2012年03期
8 谭柱华;盖秉政;庞宝君;贾斌;;影响Hopkinson压杆实验结果因素的数值模拟分析[J];哈尔滨工业大学学报;2007年03期
9 李耀;李和平;巫绪涛;;混凝土HJC动态本构模型的研究[J];合肥工业大学学报(自然科学版);2009年08期
10 纪冲,龙源,万文乾;弹丸侵彻钢纤维混凝土数值模拟[J];解放军理工大学学报(自然科学版);2005年05期
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