冲击和快速加载作用下钢筋混凝土梁柱构件性能试验与数值模拟研究

发布时间：2018-05-25 09:53

本文选题：钢筋混凝土长柱 + 钢筋混凝土短柱　；参考：《湖南大学》2014年博士论文

【摘要】：地震和冲击荷载等强动力荷载作用造成钢筋混凝土结构破坏,从而导致大量的人员伤亡和巨大的财产损失。钢筋混凝土结构在地震和冲击荷载等强动力荷载作用下存在的应变率效应使其动力性能与静态性能存在较大差异。在冲击荷载下受复杂的应力波传播和惯性效应的影响,结构行为更加复杂。在地震作用的应变率范围内,钢筋混凝土柱的轴向受压动力行为及考虑箍筋约束效应和应变率效应的钢筋混凝土柱的动力行为的试验资料和数值分析研究十分缺乏。在混凝土结构抗冲击性能研究方面,少见无腹筋梁和深梁的抗冲击行为研究的文献,配箍筋钢筋混凝土梁的在冲击荷载下的剪切行为的试验研究数量仍十分有限,对冲击过程中梁的加速度响应及其分布变化未进行详细探讨,影响梁的冲击响应的相关因素(比如配箍率、剪跨比等)的探讨还不够全面。基于此,本文采用试验和数值分析研究相结合的方法,在地震作用的应变率范围内对钢筋混凝土柱的动力行为以及冲击荷载下钢筋混凝土梁和深梁的动力行为进行研究。本文的主要研究工作如下： (1)开展了两种不同长细比的钢筋混凝土长柱快速轴心受压加载试验和动力有限元模拟研究,分析了快速加载对不同长细比的柱动态承载力及其对应的变形的影响,阐述了不同长细比的轴心受压柱动态承载力提高的机制,即快速加载下应变率效应和惯性效应在不同长细比下的影响规律。 (2)提出了同时考虑应变率效应和箍筋约束效应的混凝土塑性模型等效单轴受压本构模型,并基于此利用ABAQUS建立了分析约束钢筋混凝土轴压短柱在快速加载下动力行为的有限元模型。算例分析表明,模拟结果与试验结果吻合良好。通过有限元模型参数分析,得到了配置箍筋构形、箍筋间距和纵筋配筋率对约束钢筋混凝土短柱在地震作用应变率范围内的动态力学性能的影响规律。 (3)开展了简支无腹筋钢筋混凝土梁的落锤冲击试验研究和有限元分析。通过试验研究重点关注冲击锤重、冲击速度和冲击能量对梁在冲击荷载下梁的破坏过程、典型破坏模式和剪切破坏面的影响,并研究了冲击力、钢筋与混凝土应变时程特点。基于应变数据,推断出梁在冲击过程中的弯矩分布及惯性力分布特点,并在此基础上对单自由度等效模型进行了讨论。采用LS-DYNA建立了分析无腹筋钢筋混凝土梁抗冲击行为的有限元模型,分析了剪跨比、梁顶是否配置纵筋对无腹筋梁的冲击响应的影响规律。 (4)开展了简支配箍钢筋混凝土梁的落锤冲击试验和有限元模拟。试验研究了不同冲击速度、冲击能量及二次冲击效应对冲击荷载下的梁抗剪行为的影响,得到了不同参数影响下梁的破坏过程、破坏模式特点,详细分析了冲击响应(包括冲击力、支座反力和位移时程曲线以及冲击力-位移曲线和支座反力-位移曲线)的特征。基于实测加速度响应,分析了冲击过程中梁的惯性力分布特点,进而讨论了不同冲击荷载作用下梁斜裂缝开裂模式差异的机理和梁的抗冲击承载力评估方法。采用LS-DYNA建立了分析冲击荷载作用下配箍钢筋混凝土梁动力行为的有限元模型,并分析了配箍率对钢筋混凝土梁的冲击响应的影响规律。 (5)首次开展了简支钢筋混凝土深梁的落锤冲击试验研究和有限元分析。通过试验研究了两种静载破坏特性的钢筋混凝土深梁在不同冲击速度及二次冲击效应下的动态行为,针对破坏过程和破坏形态、冲击力、跨中位移响应的特点进行了分析,并讨论了深梁的抗冲击承载力的评估方法。采用LS-DYNA建立了分析深梁抗冲击行为的有限元模型,并用试验数据进行了验证,进而研究了配箍率对钢筋混凝土深梁在冲击荷载下的动态响应的影响规律。
[Abstract]:Strong dynamic loads, such as earthquakes and impact loads, cause damage to reinforced concrete structures, resulting in a large number of casualties and huge property losses. The effect of strain rate on the dynamic performance and static performance of reinforced concrete structures under strong dynamic loads, such as earthquake and impact loads, makes a great difference between the dynamic performance and the static performance. Under the influence of complex stress wave propagation and inertia effect, the structural behavior is more complex. In the range of strain rate, the axial compression dynamic behavior of reinforced concrete columns and the experimental data and numerical analysis of the dynamic behavior of reinforced concrete columns considering the confinement effect and strain rate effect of the stirrup and strain rate are very short. In the study of the impact resistance of concrete structures, the study of impact resistance behavior of non abdominal tendons and deep beams is rare. The number of shear behavior of reinforced concrete beams with stirrup reinforced concrete beams under impact loads is still very limited. The acceleration response and distribution of beams in the process of impact are not discussed in detail, affecting the impact of the beams. In this paper, the dynamic behavior of reinforced concrete columns and the dynamic behavior of steel reinforced concrete beams and deep beams under the impact load are studied in this paper. The main research work of this article is as follows:
(1) two kinds of reinforced concrete long columns with different length and slenderness ratio are carried out by fast axial compression loading test and dynamic finite element simulation. The effect of fast loading on the dynamic bearing capacity of columns with different length and slenderness ratio and its corresponding deformation is analyzed. The mechanism of improving the dynamic bearing capacity of the axial compression column with different length and fineness ratio is described, that is, fast loading The influence of different slenderness ratio on the strain rate effect and inertial effect under different slenderness ratios.
(2) an equivalent uniaxial compression constitutive model of concrete plastic model is proposed, which considers both the strain rate effect and the confinement effect of the stirrup. Based on this, a finite element model for the dynamic behavior of a confined reinforced concrete axial compression short column under rapid loading is established by using ABAQUS. The numerical example shows that the simulation results are in good agreement with the experimental results. Through the analysis of the parameters of the finite element model, the influence of the configuration of the stirrup, the spacing of the stirrup and the reinforcement ratio of the longitudinal reinforcement on the dynamic mechanical properties of the confined reinforced concrete short columns in the range of the earthquake action strain rate is obtained.
(3) the drop hammer impact test and finite element analysis of a simple supported reinforced concrete beam with no abdominal tendon are carried out. The damage process of the beam under impact load, the impact of the typical failure mode and the shear failure surface on the beam under impact load, and the impact force, the strain of the reinforced concrete and the concrete are studied. Based on the strain data, the bending moment distribution and the characteristics of the inertia force distribution of the beam in the process of impact are deduced. On the basis of this, the equivalent model of single degree of freedom is discussed. The finite element model for the analysis of the anti impact behavior of the reinforced concrete beams with no abdominal tendons is established by LS-DYNA. The influence of the impact response of the girders of the abdominal tendons.
(4) the impact test and finite element simulation of reinforced concrete beams with simply dominated stirrup are carried out. The effects of different impact velocity, impact energy and two impact effects on the shear behavior of beams under impact load are studied, and the failure process of the beams under the influence of different parameters and the characteristics of the failure mode are obtained. The impact response is analyzed in detail. The characteristics of the impact force, the support reaction and displacement time history curve, the impact force displacement curve and the support reverse force displacement curve. Based on the measured acceleration response, the characteristics of the beam's inertia force distribution in the impact process are analyzed, and the mechanism of the split mode difference and the impact bearing capacity of the beam under different impact loads are discussed. The finite element model of the dynamic behavior of stirrup reinforced concrete beams under impact loading is established by LS-DYNA, and the influence of the stirrup rate on the impact response of reinforced concrete beams is analyzed.
(5) the impact test study and finite element analysis of the simple supported reinforced concrete deep beam are first carried out. The dynamic behavior of the reinforced concrete deep beams with two static loading characteristics under different impact velocity and two impact effects is studied by experiments. The characteristics of the failure process and failure mode, the impact force and the response of the middle span displacement are carried out. The method of evaluating the impact bearing capacity of deep beams is discussed. The finite element model of the impact behavior of deep beams is established by LS-DYNA, and the test data are used to verify the influence of the stirrup rate on the dynamic response of the reinforced concrete deep beam under the impact load.
【学位授予单位】：湖南大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU375.1

【参考文献】