混凝土类材料SHPB实验若干问题探讨

发布时间：2018-01-12 16:03

  本文关键词：混凝土类材料SHPB实验若干问题探讨　出处：《工程力学》2014年05期 　论文类型：期刊论文

  更多相关文章： 混凝土类材料 霍普金森压杆实验 数值模拟 惯性效应 围压 温度 三维细观模型

【摘要】：分离式霍普金森压杆(SHPB)实验是研究混凝土类材料动态力学性能的主要方法。该文简要回顾了当前混凝土类材料SHPB实验中存在的若干问题(如端面摩擦、骨料大小、惯性效应、温度效应等)的研究进展;通过对混凝土SHPB实验的精细化数值模拟,进一步分析了惯性效应产生机理,提出了材料的塑性流动引起的横向加速度是产生围压的关键原因,围压波在试件中心的反射和边缘的卸载形成试件中围压从中心向四周逐渐减小的抛物线型分布;利用该文所提的SHPB实验惯性效应产生机理,较好地解释了SHPB实验的尺寸和主动围压的影响规律;基于自主研制的可进行围压和温度共同加载的SHPB实验装置TSCPT-SHPB,对在5MPa~25MPa围压作用下以及在40℃~80℃温度下盐岩动态力学性能进行实验研究,结果表明,高围压下应变率效应不如低围压下显著,温度越高,强度越低;基于考虑粗骨料大小、形状及空间随机分布的三维混凝土细观模型,对混凝土各细观组分对动态效应影响进行了研究,结果表明:各组分材料静态强度越高,混凝土动态强度也越高;在相同骨料粒径条件下,骨料体积率越高,混凝土动态强度也越高;而相同骨料体积含量条件下,骨料尺寸越大,混凝土动态强度越低。
[Abstract]:The split Hopkinson compression bar test is the main method to study the dynamic mechanical properties of concrete materials. In this paper, some problems existing in the SHPB experiments of concrete materials are briefly reviewed. (. Such as face friction. The research progress of aggregate size, inertia effect, temperature effect, etc. Through the detailed numerical simulation of concrete SHPB experiment, the mechanism of inertia effect is further analyzed, and the key cause of confining pressure is the transverse acceleration caused by plastic flow of material. The reflection of the confining pressure wave in the center of the specimen and the unloading of the edge form the parabolic distribution in which the confining pressure gradually decreases from the center to the periphery. Based on the mechanism of inertial effect in SHPB experiment proposed in this paper, the influence law of size and active confining pressure of SHPB experiment is well explained. Based on the self-developed SHPB experimental device TSCPT-SHPB which can load confining pressure and temperature together. The dynamic mechanical properties of salt rock under 5 MPA confining pressure and 40 鈩，

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