【作者】 曲嘉；

【导师】 何蕴增； 邹广平；

【作者基本信息】 哈尔滨工程大学 ， 固体力学， 2010， 博士

【摘要】 钢纤维混凝土(Steel Fiber Reinforce Concrete)是由水泥浆、砂、骨料和乱向分布的钢纤维所组成。钢纤维混凝土由于钢纤维改善了混凝土的抗拉性能、增强了韧性,所以在隧洞衬砌、铁路轨枕、核反应堆安全壳、管道工程、大跨建筑物、大型防御工事、大型桥梁、机场等军用和民用建筑上得到了广泛的工程应用。而以上大型混凝土结构在其使用过程中,不可避免的要受到地震、爆炸等动态或冲击荷载的作用,因此研究钢纤维混凝土的强度问题具有重要的理论意义和广泛的工程应用背景,本文主要工作如下:1.借鉴巴西圆盘劈拉实验方法,提出了混凝土材料的圆球型试样劈拉实验原理和具体操作方法。该方法可以采用普通的万能材料试验机实现混凝土类材料三轴压/拉/拉(C/T/T)等比加载,且测试的强度正好处于拉子午线上。推导了巴西圆盘试样劈拉强度和圆球型试样劈拉强度与八面体应力、罗德角之间的换算公式。基于上述实验原理,本文对钢纤维掺量为1%的混凝土试样行了实验测试。2.采用有限元方法研究了波形整形器对分离式霍普金森压杆装置入射应力波的影响,并得到了入射波上升沿随波形整形器的厚度的增加和直径的减小而趋于平缓的结果。3.借鉴分离式霍普金森压杆测试巴西圆盘劈拉强度的方法,建立了圆球型试样冲击劈拉强度的测试方法,并对钢纤维掺量为1%的混凝土试样进行了实验测试,得到了巴西圆盘试样和圆球型试样的动态增强因子。4.借鉴准静态三点弯曲试样测试断裂韧性的方法,建立了采用楔型头分离式霍普金森压杆装置对三点弯曲试样进行断裂韧性测试的方法;通过对钢纤维掺量为1%的混凝土试样进行准静态和冲击试验,得到了低、高应变率下的平面应变断裂韧性。5.结合钢纤维混凝土偏平面强度包络线的特性,对Ottosen强度理论模型进行简化,提出了适用于钢纤维混凝土的抛物线型强度准则计算模型。6.提出了动态增强因子线性计算模型,该模型具有形式简单、计算方便、物理意义明确等特点。7.结合抛物线型强度准则计算模型和拉伸动态增强因子的线性计算模型,提出了适用于钢纤维混凝土的抛物线型动态强度准则计算模型。本文得出的研究结果可以为钢纤维混凝土材料的设计、生产、应用以及工程爆破提供一定的参考依据。更多还原

【Abstract】 Steel Fiber Reinforce Concrete(SFRC) is made of hydraulic cements containing sand, aggregate and with randomly oriented steel fibers. Because the steel fibers reinforced the tension strength and toughness of the concrete, Steel Fiber Reinforce Concrete has been used as a construction material for tunnels, railway sleepers, nuclear reactor containment, airdrome, bridges, buildings and structures. During the using, the structures were unavoidable impacted by earth shake, blast and etc. Therefore, theoretically and practically, it is important to study the strength problem of steel fiber concrete. The main content of this paper includes:1. By the Brazilian disc split method, the spilt principle for the radial compression of rotating spheroid has been discussed. This method can realize C/T/T proportional loading by ordinary universal testing machine and the tested strength point with the Rode angelθ≡60 is on tension meridian line. The split principle and detailed operation method for concrete sphere specimen has been presented. The transform equation concerning Brazilian disc split strength, sphere specimen split strength, octahedral stress and the Rode angel has been obtained. The concrete specimen with 1% steel fiber has been tested.2. The influence of pulse shaper on the incident stress waver of split Hopkinson press bar has been calculated by FEM. The results show that the incident wave increases with the increase of thickness and reduction of diameter of the pulse shaper.3. The method to obtain the split strength of Brazilian disc by split Hopkinson press bar has been used to establish the testing method to gain the split strength of sphere specimen. The dynamic increase factors of Brazilian disc and sphere specimen has been obtained by the experiment on the concrete specimen with 1% steel fiber.4. The quasi-static three point bending fracture toughness test has been introduced to establish a series of fracture toughness testing methods by wedge split Hopkinson press bar on three point bending specimen. The plane strain fracture toughness under high and low strain rate has been obtained by the quasi-static and shock experiments on the concrete specimen with 1% steel fiber.5. The Ottosen theoretical model has been simplified by the property of the deviatonic stress plane envelope line of steel fiber concrete. The parabolic strength criterion model has been firstly presented for steel fiber concrete.6. Based on the experimental data, the linear computational model for dynamic increase factor has been presented, which is in simple form, easy to calculate and physically distinct and meets well with the experimental data.7. By the parabolic strength criterion model and the linear computational model of tension dynamic increase factor, the parabolic dynamic strength criterion model has firstly represented for steel fiber concrete. The results can provide some useful reference for the design, production, application and blast for steel fiber concrete.更多还原