素混凝土冲击动力学性能精细化研究

发布时间：2018-08-03 10:46

【摘要】：在对素混凝土的冲击动力学测试中，通常会存在惯性效应和摩擦效应，这些效应进入了最后的测试结果，为试验带来了不必要的误差甚至会导致错误。目前已经有许多研究描述了这方面的研究成果，然而，对于素混凝土材料惯性效应和摩擦效应导致素混凝土在动态荷载作用下的动态强度改变的机理方面的学术争论至今仍无法统一。因此，本文以C40素混凝土为基础，对不同尺寸的素混凝土试件进行准静态压缩试验和动态压缩试验，同时还对素混凝土试件的动态压缩试验进行了数值模拟，分析了惯性效应和摩擦效应对素混凝土动态强度、素混凝土动态增强因子（DIF）的影响，具体包括以下工作： 1.对尺寸为Φ22mm×11mm、Φ32mm×16mm、Φ40mm×20mm的素混凝土试件进行了准静态压缩试验，分析了惯性效应对素混凝土试件准静态压缩试验结果的影响。对尺寸为Φ32mm×10mm、Φ32mm×20mm、Φ32mm×30mm的素混凝土试件进行了静摩擦系数测定和准静态压缩试验，分析了摩擦效应对准静态压缩试验结果的影响。通过对试验数据的分析，得到了素混凝土试件的荷载-时间关系。 2.对素混凝土试件在SHPB动态压缩试验中的惯性效应和摩擦效应进行了理论分析。 3.使用SHPB试验装置对上述六种尺寸的素混凝土试件进行了动态压缩试验，并通过对试验数据的分析处理得到了SHPB试验过程中的应力波的变化图，素混凝土试件的应变率-时间变化曲线、应力-应变关系、峰值应力-应变率关系等等。分析了惯性效应和摩擦效应对素混凝土试件动态强度的影响。 4.提出了素混凝土的动态增强因子（DIF）与应变率之间的关系表达式，，同时还分析了惯性效应和摩擦效应对素混凝土动态增强因子（DIF）的定量影响。 5.使用HJC本构模型通过有限元软件ANSYS/LS-DYNA对素混凝土试件的SHPB动态压缩试验进行了数值模拟，并将数值模拟结果和试验结果进行了对比分析。最后，通过对本论文进行总结，指出了一些本课题需要改善和进一步研究的内容。
[Abstract]:In the test of impact dynamics of plain concrete, inertia effect and friction effect usually exist. These effects come into the final test result, and bring unnecessary error to the test and even lead to error. Many studies have described the results, however, The academic debate on the mechanism of dynamic strength change of plain concrete under dynamic load caused by inertia effect and friction effect of plain concrete is still not uniform. Therefore, based on C40 plain concrete, quasi static compression test and dynamic compression test are carried out for different size plain concrete specimens. At the same time, the dynamic compression tests of plain concrete specimens are numerically simulated. The influence of inertia effect and friction effect on the dynamic strength of plain concrete and the dynamic enhancement factor of plain concrete (DIF) are analyzed, including the following work: 1. The quasi-static compression tests of plain concrete specimens with size 桅 22mm 脳 11mm, 桅 32mm 脳 16mm and 桅 40mm 脳 20mm were carried out. The influence of inertia effect on the results of quasi-static compression tests of plain concrete specimens was analyzed. The static friction coefficient and quasi-static compression test of plain concrete specimens of 桅 32mm 脳 10mm, 桅 32mm 脳 20mm and 桅 32mm 脳 30mm were measured. The effect of friction effect on the results of static compression tests was analyzed. By analyzing the test data, the load-time relationship of plain concrete specimens is obtained. 2. 2. The inertia effect and friction effect of plain concrete specimen in SHPB dynamic compression test are analyzed theoretically. 3. The dynamic compression tests of the six kinds of plain concrete specimens mentioned above were carried out by using the SHPB test device, and the change diagram of the stress waves during the SHPB test was obtained by analyzing and processing the test data. The strain rate-time curve, stress-strain relation, peak stress-strain rate relationship of plain concrete specimens are discussed. The influence of inertia effect and friction effect on the dynamic strength of plain concrete specimen is analyzed. 4. The relationship between dynamic enhancement factor (DIF) and strain rate of plain concrete is presented. The quantitative effects of inertia effect and friction effect on (DIF) of plain concrete dynamic enhancement factor are also analyzed. The HJC constitutive model was used to simulate the SHPB dynamic compression test of plain concrete specimens by the finite element software ANSYS/LS-DYNA, and the numerical simulation results were compared with the experimental results. Finally, through the summary of this paper, some contents that need to be improved and further studied are pointed out.
【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

【参考文献】