爆炸荷载作用下建筑玻璃的破碎分析

发布时间：2019-06-27 19:43

【摘要】：意外发生的爆炸事故和有目的的炸弹袭击时有发生,统计表明,爆炸事故中70%的伤亡是由于爆炸冲击作用对建筑玻璃造成破坏后产生的高速飞溅碎片带来的二次伤害所造成。因此,建筑玻璃的抗爆性能研究成为人们关注的热点。采用传统的基于侵蚀算法的单元删除法模拟玻璃裂纹的生成,由于单元删除造成的质量损失及能量不守恒,体系的控制方程不再成立,导致数值模拟结果准确性不高。本文基于有限元显式动力分析软件LS-DYNA,提出采用节点分离方法模拟爆炸荷载作用下玻璃裂纹的产生,避免单元的删除,保证体系控制方程成立。分别采用节点分离法与单元删除法对某一现场爆炸试验中玻璃板的破碎进行数值模拟,同时采用统计学方法对两种方法下数值模拟结果的玻璃碎片尺寸分布、抛射速度分布以及抛射距离分布进行了详细统计。对比数值模拟结果发现,节点分离法得到的碎片最大抛射速度、最远抛射距离以及玻璃破碎形态与试验吻合的更好,节点分离法的准确度高于单元删除法。统计结果表明:两种方法下,随着爆炸比例距离的减小,生成的小碎片越多,抛射速度越大,抛射距离越远;节点分离方法在模拟玻璃小尺寸碎片方面更具优越性。
[Abstract]:Accidental explosions and purposeful bomb attacks occur from time to time. Statistics show that 70% of the casualties in the explosion accidents are caused by the secondary damage caused by high speed splashing fragments caused by the damage to building glass caused by explosion impact. Therefore, the study of explosion resistance of building glass has become the focus of attention. The traditional element deletion method based on erosion algorithm is used to simulate the generation of glass cracks. Due to the mass loss and non-conservation of energy caused by element deletion, the governing equation of the system no longer holds, resulting in the accuracy of numerical simulation results is not high. In this paper, based on the finite element explicit dynamic analysis software LS-DYNA, a node separation method is proposed to simulate the generation of glass cracks under explosive load, to avoid the deletion of elements and to ensure the establishment of the control equation of the system. Node separation method and element deletion method are used to simulate the broken glass plate in a field explosion test, and the glass fragment size distribution, ejection velocity distribution and ejection distance distribution of the numerical simulation results under the two methods are counted in detail by statistical method. Compared with the numerical simulation results, it is found that the maximum ejection velocity, the farthest ejection distance and the broken shape of glass obtained by the node separation method are in good agreement with the experimental results, and the accuracy of the node separation method is higher than that of the element deletion method. The statistical results show that with the decrease of explosion proportional distance, the more small fragments are generated, the greater the ejection speed is, and the farther the ejection distance is, and the node separation method is more superior in simulating small size fragments of glass.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU524;TU312.3

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