基于LS-DYNA仿真模拟车—桥墩碰撞及损伤评估研究

发布时间：2018-02-15 10:33

本文关键词： 车-桥墩碰撞撞击力 LS-DYNA 损伤评估　出处：《华东交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着我国交通事业的迅速发展，道路交通量和桥梁建设的总量也在与日俱增，由此也带来了越来越频繁的车桥碰撞相关问题。目前，在全世界范围内车桥碰撞已经造成了许多次的灾难性事故，如此大的人员伤亡和经济损失也使得这一问题引起了全世界的重视。对于我国在这一问题上的研究还远不足够，我国在考虑车桥撞击力问题上还没有专门的规范公式来参照使用，而相关的规范中仅规定了车-护栏撞击方面，并未涉及车-桥墩撞击，因此我国在这一问题上的规范还不够符合实际的情况，应当予以完善。现在许多学者正分别从不同的角度来研究车-桥墩撞击的相关问题，，本篇论文即是利用LS-DYNA软件仿真模拟车-桥墩碰撞并进行研究分析，主要工作如下：（1）研究分析国内外学者对车桥碰撞问题的相关成果，首先整理他们的分析思路和主要研究对象，并评估不同研究方法的优势与劣势，再结合自身的研究设备从而确定自己的研究思路。（2）利用ANSYS/LS-DYNA软件分别建立车辆和桥梁的有限元模型。首先在建立模型的过程中还要兼顾材料仿真与保证运算速度等方面的特点，合理的进行选择材料模型及各相关的参数。再次从能量的角度对有整体的有限元模型进行验证，确定该模型用于车-桥墩碰撞模拟的准确性及合理性。（3）利用LS-DYNA软件对影响车-桥墩最大撞击力的各主要因素进行分别模拟仿真，即墩底边界条件、汽车质量、缓冲器、碰撞速度和碰撞角度五大因素。通过仿真模拟得出相关数据，用以分析最大撞击力与各因素之间的变化规律。（4）对不同因素下受撞桥梁进行损伤评估，分别从总体损伤和局部损伤两个方面进行评估。对于总体损伤评估，主要是以墩台的轴向力承载力的变化率与规范评定标准进行的评估；而对于局部损伤评估，主要是依靠PREPOST后处理器分别提取出各因素撞击下的墩顶的水平位移、沉降及墩底应力，将其与规范限值进行对比进行损伤评估。结果表明车-桥墩碰撞时的各因素的变化与规范下的车-护栏碰撞并不相同，且所带来的对桥梁的损伤有时是致命的，因此在桥梁设计需要加强对汽车这一偶然撞击的考虑，同时还应当规范进一步地完善。
[Abstract]:With the rapid development of China's transport, the total volume of traffic and bridge construction in bridge which brings grow with each passing day, more and more frequent collision related problems. At present, in the world bridge collision has caused many times of catastrophic accidents, such as the large casualties and economic losses but also makes this problem has aroused the attention of the world. The research on this problem in our country is far from enough, our country in terms of the impact force is no standard axle formula to a special reference to the use of the relevant specifications, and only provides car barrier impact, did not involve car pier collision therefore, in this issue of the standard of our country is not enough to meet the actual situation, it should be perfected. Now many scholars are from different angles to study the vehicle bridge pier impact related problems, this paper is The LS-DYNA software is used to simulate the collision of the bridge pier and carry on the research and analysis. The main work is as follows:
(1) research and analysis of domestic and foreign scholars on vehicle bridge collision problems. First, organize their analysis ideas and main research objects, and evaluate the strengths and weaknesses of different research methods, then combine their own research equipment, so as to identify their research ideas.
(2) finite element models of vehicle and bridge by using ANSYS/LS-DYNA software. Firstly, the operation speed but also take into account the characteristics of materials such as simulation and guarantee in the model building process, reasonable selection of material model and the related parameters. Again from the energy angle of a complete finite element model is verified. The model is used to determine the accuracy of simulation of vehicle collision and rationality.
(3) the main factors affecting vehicle using LS-DYNA software on the pier of the maximum impact force were simulated, the pier bottom boundary conditions, vehicle quality, buffer, impact velocity and impact angle of five factors. Through the simulation that the related data is used to analyze the variation between the maximum impact force and other factors.
(4) under the impact of different factors for damage assessment of bridges, were evaluated from the two aspects of the overall damage and local damage. The damage assessment is mainly to assess the changes of axial force of pier bearing capacity ratio and standard criterion for evaluation; and for the local damage assessment, mainly rely on PREPOST processors are extracted from various factors under the impact of the horizontal displacement of pier top and bottom of the pier settlement, stress, and the specification limits are compared for damage assessment. The results show that the changes of various factors and standard vehicle collision pier under the car barrier crash is not the same, and brought to the bridge the damage is sometimes fatal, so in the design of bridges need to strengthen the impact of the car accident, also should be standardized further perfect.

【学位授予单位】：华东交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U447

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