爆炸冲击荷载作用下框架结构抗倒塌性能研究

发布时间：2018-01-04 02:07

本文关键词：爆炸冲击荷载作用下框架结构抗倒塌性能研究　出处：《福州大学》2014年硕士论文　论文类型：学位论文

【摘要】：当前由于燃气泄漏、易燃易爆品堆置不当等原因所引起的爆炸时有发生,使得建筑结构受到爆炸冲击荷载而发生倒塌的可能性增大。框架结构作为我国民用建筑中应用最为广泛的结构形式,若其主要受力构件的梁、柱等在爆炸冲击荷载作用下发生了破坏,将导致结构局部区域失去承载能力,进而引发整体的连续性倒塌,可能造成严重的人员伤亡和社会影响。因此,对RC框架结构在爆炸冲击荷载作用下的抗倒塌性能进行研究,有着重要的理论意义和工程应用价值。但目前为止,结构抗连续性倒塌研究主要还是集中在静力分析方法上,与爆炸荷载相关的研究成果还非常少。有鉴于此,本文以一榀RC框架试验模型作为研究对象,基于数值模拟分析对爆炸冲击荷载作用下该结构的抗倒塌性能进行了较深入的研究。论文的主要研究成果包括以下几个方面：(1)首先从静力分析角度出发,对现有的构件重要性系数方法进行改进,以此分析框架结构各构件在特定荷载作用下的倒塌顺序。同时,基于ANSYS/LS-DYNA程序数值模拟了框架的倒塌过程,并与试验实测位移进行了对比。此外,也将理论分析的倒塌顺序和数值模拟结果进行了对比。通过相互比较,验证了模型的正确性。(2)其次,对爆炸冲击荷载的相关基本理论进行了归纳总结。研究了爆炸荷载分类、基本参数、压力时程曲线衰减关系、爆炸冲击波的基本概念和爆炸冲击荷载计算方法等内容,并由此确定了本文所采用的爆炸荷载加载方法。同时对数值模拟过程所需的材料本构模型、边界条件和构件连接条件、空气与炸药单元网格尺寸等方面进行了分析。(3)再次,基于ANSYS/LS-DYNA程序研究了爆炸冲击荷载作用下RC框架的动力响应及倒塌过程。重点研究了爆炸冲击波与框架结构的相互作用、框架结构构件的动力响应、框架结构在局部关键构件失效后的连续倒塌过程等三个方面。(4)最后,采用关键构件法与拉结强度法对框架结构进行加强,以防止结构发生倒塌并提出相关设计建议。研究结果表明：加密柱子箍筋、增大梁的纵筋配筋率以及在梁上设置外部拉结钢筋均能有效提高框架的抗倒塌能力。而单纯增加柱子的纵筋配筋率没有明显的效果。总体来说,本文通过渐进式的分析过程,首先从静力方面验证了框架模型的正确性,再以此作为爆炸冲击下动力分析的基准模型,最后结合动力分析结果提出了相关加强结构抗倒塌性能的设计建议,因此实现了完整的爆炸冲击荷载下框架结构的倒塌性能分析流程。
[Abstract]:The current due to gas leak, flammable and explosive goods stacking improperly caused when the explosion occurred, the building structure subjected to blast loading and collapse. The possibility of increasing the frame structure as China's civil widely used, if the main stress components of beam column happened damage under explosion loading, will cause the local structure lose the bearing capacity, and thus lead to progressive collapse of the whole, may cause casualties and serious social impact. Therefore, research on anti collapse performance of RC frame structure in the explosion load hit down, has important theoretical significance and engineering application value. But so far, the research of progressive collapse resistance is mainly concentrated on the static analysis method, there is very little research achievements related to explosive load. In view of this, this paper In a RC test framework model as the research object, numerical simulation analysis on anti collapse performance of the structure under blast loading is studied. Based on the research results of this paper are as follows: (1) firstly from the perspective of static, the importance coefficients of components existing methods are improved. In order to analyze the collapse sequence of each member of a frame structure in a particular load. At the same time, the ANSYS/LS-DYNA program numerical simulation of collapse process based on the framework, and compared with the measured displacement. In addition, the order will also collapse the results of theoretical analysis and numerical simulation were compared. Through comparison, verify the correctness of the model. (2). Secondly, summarizes the basic theory of explosion shock loading. The explosion load classification, basic parameters, pressure time curves of attenuation relationship Department of basic concepts and contents of explosion shock wave blast load calculation method, and thus determine the explosive loading method used in this paper. At the same time, the constitutive model of the numerical simulation process of required materials, boundary conditions and component connection conditions were analyzed with single air explosive element mesh size and so on. (3) again, based on the ANSYS/LS-DYNA program to study the dynamic response and collapse process of RC frame under blast loading. Focus on the interaction of shock wave and frame structure, dynamic response of frame structure, frame structure in three aspects of local key components after the failure of the progressive collapse process (4) finally. The key component, and Rachel strength method of frame structure strengthened to prevent structural collapse and put forward relevant suggestions of design. The results show that: the encryption column stirrup,. The beam longitudinal reinforcement ratio and is arranged outside the beam Rachel reinforced frame can effectively improve the anti collapse capacity. And simply increasing the column longitudinal reinforcement ratio has no obvious effect. In general, the asymptotic analysis process, first the correctness of model validation framework from static aspect. As the benchmark model analysis under explosive impact force, finally combined with the results of dynamic analysis and design suggestions are put forward to strengthen the relevant structural anti collapse performance, thus realizing the collapse performance of the frame structure under blast loading complete process of analysis.

【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU375.4

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