某钢厂行车梁内爆炸事故的数值模拟分析

发布时间：2018-03-04 04:28

本文选题：行车梁　切入点：密闭结构　出处：《华侨大学》2013年硕士论文　论文类型：学位论文

【摘要】：随着城市化的发展，密闭空间广泛存在于公共交通系统、煤气管道、爆炸仓库、爆竹生产厂房等与日常生活息息相关的结构当中，在这些密闭空间结构里，内爆炸事故时有发生。其中，2012年5月，广东某钢厂内一行车梁发生内爆炸事故，造成重大人员伤亡及周围设施不同程度的毁坏。该行车梁作为一类金属密闭结构，其爆炸特点有别于其它结构，，有必要对其内爆炸事故进行分析，探讨未明爆炸过程及未知爆炸源的等效TNT当量。论文用高能炸药代替行车梁爆炸事故中的未知爆炸源，对行车梁在内爆炸荷载作用下的破坏过程和内爆炸冲击波传播过程进行研究，主要研究方法和过程如下：（1）利用有限元软件ANSYS/LS-DYNA进行空中自由爆炸的数值模拟，将数值计算结果与经验公式对比，计算结果吻合较好，证明论文数值模型及材料参数选取的可靠性，为结构抗爆分析做准备。（2）利用有限元软件ANSYS/LS-DYNA建立合理的行车梁有限元计算模型，调整钢材失效应变与TNT当量大小，将数值模拟结果与行车梁的实际破坏情况进行对比，当两者结果较为一致时，确定其时失效应变和TNT当量为合理值，并从行车梁壁板的应力、应变分布和位移时程曲线角度分析行车梁的破坏全过程。（3）考虑TNT当量大小、爆炸点位置的影响，利用有限元软件ANSYS/LS-DYNA建立模型进行模拟，分析行车梁内腔的冲击波压力分布情况。通过以上模拟分析，得到如下结论：（1）行车梁爆炸事故中未知爆炸源的等效TNT当量为122.25kg；（2）行车梁所用钢板的失效应变值为0.35；（3）行车梁内爆炸冲击波沿着内壁板传播并在角隅堆积，行车梁腹板与下盖板的连接为较弱的单面角焊缝连接以及下盖板产生较大的位移响应，是造成行车梁破坏的主要原因；（4）提高焊缝强度，增大钢材失效应变以及加劲肋的设置有利于减小行车梁在爆炸作用下的破坏。
[Abstract]:With the development of urbanization, confined spaces are widely used in public transport systems, gas pipelines, explosive warehouses, firecracker production plants and other structures closely related to daily life. In these confined space structures, Internal explosion accidents occur from time to time. Among them, in May 2012, an internal explosion accident occurred in a driving beam of a steel works in Guangdong province, resulting in heavy casualties and damage to the surrounding facilities to varying degrees. The beam is a kind of metal closed structure. The explosion characteristics are different from those of other structures. It is necessary to analyze the internal explosion accident and to discuss the equivalent TNT equivalent of the unknown explosion source and the unknown explosion process. In this paper, the failure process and the propagation process of the inner explosion shock wave are studied by replacing the unknown explosion source in the train beam explosion with high explosive charge. The main research methods and processes are as follows: (1) using finite element software ANSYS/LS-DYNA to simulate the free explosion in the air, the numerical results are compared with the empirical formulas, and the calculated results are in good agreement with each other. It is proved that the reliability of the numerical model and the selection of material parameters is proved, and the structural anti-explosion analysis is prepared. The finite element software ANSYS/LS-DYNA is used to establish a reasonable finite element model of the crane beam, and the failure strain of steel and the equivalent value of TNT are adjusted. The numerical simulation results are compared with the actual failure conditions of the train beam. When the results are consistent, the time failure strain and TNT equivalent are determined as the reasonable values, and the stress of the train beam slab is obtained. Strain distribution and displacement time history curve angle are used to analyze the whole failure process of train beam. Considering the influence of TNT equivalent and the location of explosion point, the finite element software ANSYS/LS-DYNA is used to establish a model to simulate the shock wave pressure distribution in the inner cavity of the driving beam. Based on the above simulation analysis, it is concluded that the equivalent TNT equivalent of the unknown explosion source in the explosion accident of the beam is 122.25 kg / kg / 2) the failure strain value of the steel plate used in the beam is 0.35 / 3) the explosion shock wave propagates along the inner wall plate and accumulates in the corner corner of the beam. The connection between the web plate and the lower cover plate of the crane beam is a weak single side fillet weld joint and a large displacement response of the lower cover plate, which is the main reason for the failure of the crane beam. Increasing the failure strain of steel and the setting of stiffening rib can reduce the damage of the beam under the action of explosion.
【学位授予单位】：华侨大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：X928.7

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