【作者】 刘斌；

【导师】 李珠；

【作者基本信息】 太原理工大学 ， 结构工程， 2008， 硕士

【摘要】 冲击是工程实际中广泛存在的一种现象。结构受冲击作用下的强度、刚度、稳定性、临界能量荷载和临界冲击力的研究属结构耐撞性研究范畴,由于结构在冲击作用下的响应是一个复杂的非线性力学问题,目前该研究领域还比较弱。尤其,对钢管混凝土结构侧向冲击的研究还是空白领域。随着钢管混凝土结构的应用日益广泛,以及层出不穷的钢管混凝土结构受冲击破坏现象的发生,对它的研究也变得十分必要。本文以两端固定的钢管混凝土柱为研究对象,以冲击荷载作用下的模型试验为前提和基础,利用有限元程序ANSYS/LS-DYNA进行了模拟分析,重点研究了轴向力作用下的两端固定柱在冲击荷载作用下的破坏模式,记录了冲击力和轴向力的时程曲线,获得并讨论了不同套箍系数和预加轴向压力等因素对构件临界冲击破坏形态的影响。本文首先进行了钢管混凝土柱的侧向冲击实验,创造性地使用了碟型弹簧轴力装置旋加轴向力,很好地解决了轴力松弛的问题,逼近了实际工况。实测了该模型在冲击荷载作用下的动力响应及破坏的过程。记录了试件在冲击力作用下的时程曲线。本文利用了显式有限元的计算理论与计算方法。对冲击接触的动力学数值计算原理及关键理论方法进行了初步研究与归纳。本文对试件进行实体建模,对实验模型进行了冲击的仿真研究,并和实验进行对比,验证了仿真结果,找出了能够合理描述实验结果的计算模型。反之,又通过模拟仿真来研究试件的冲击形态。这样,不但得出了实验无法得到的数据,而且有效地减少了实验次数,降低了实验的成本。在仿真模拟过程中,研究了落锤在不同冲击速度下试件的挠度、冲击力应变的大小及分布规律。完成了挠度和冲击力的时程曲线,并找出了本文试件的临界能量。最后通过实验和计算机模拟表明:钢管混凝土构件具有良好的抗冲击作用,在构件受到突加荷载作用时,表现出了很好的延性。钢管混凝土受到侧向冲击时,材料有明显的屈服阶段。落锤的速度越高和质量越大,构件的动力响应越明显。更多还原

【Abstract】 The impact is a kind of phenomenon existing extensively in project reality. The research of intensity, rigidity, the stability, critical energy and critical impact force belongs to the fields of structure impact resistance, which the structure is struck in the impact load. Because the response of the structure in impact load is a complicated non-linear mechanics problem, the research of this field is still lacking, especially, on the lateral impact of the CFST. As the application of the CFST being developed day by day and accident of CFST being destroyed in impact load emerge in an edless stream, the research of the CFST structure impact characteristic is becoming very essential. In this paper, taking the CFST column with fixed-fixed boundary condition as subject investigated, baseing on the model test in impact load, utilizing finite element software ANSYS/LS-DYNA to go on a large amount of computational analysis. Primarily studing the failure mode of CFST column with fixed-fixed boundary condition under lateral impact, recording the time historytime curve of impact and axial force.In the paper, first, impact experiment has been carried on. Creatively useing disc spring axis force device to exert axis force , have resolved the axis force relaxation. The dynamic response and destruction course of the model is measured in impact load. The travel time curve of the test specimen is drow up on the drop hammer. In this paper, the explicit finite element calculation theory is applied, and the explicit finite element and computed technology has been summarized. It has been basically researched on numerical calculation principle and theoretics method of the impact contact dynamics.In this paper, entity’s modeling is bulid, and then impact realistic simulation of the test model is studied. Contrasted to the experimentation, the simulate results has been verified. Further the computational model is searched, which can describe the test results reasonably. On the contrary, through a large amount of simulation, the impact resistance of test sample is discussed. In this way, the experimental number and the cost are effectively reduced.In the course of simulation, it is studed that the deflection, strain, stress, size of impacting force and regularities of distribution of the test sample when the drop hammer with different impact speed. While the deflection and impacting force curve are made and the critical energy of sample has been found out.Finally, it is shown by means of test and computer simulation: The CFST has good resistance to impact load, when the component is added the loads suddenly, the CFST demonstrates very good ductility. When the CFST is subjected to the lateral impact load, the materials have obvious yield stadge. The bigger the speed and quality of the drop hammer, the more fragile of CFST dynamic response.更多还原