【作者】 黄亮；

【导师】 尹华伟；

【作者基本信息】 湖南大学 ， 结构工程， 2021， 硕士

【摘要】 近年来恐怖袭击和意外爆炸事件越来越多,使得结构抗爆得到更多重视,如何提高建筑结构的抗爆性能,已成为当今研究的焦点之一。钢筋混凝土板构件一直以来都是研究的热点,对于实心钢筋混凝土板来说,在爆炸作用下,大多由于背部受拉导致产生碎片,进而对人产生生命危害。为减小爆炸荷载对钢筋混凝土板的伤害,本文提出了薄壁波纹管防护结构以及吸能芯层钢筋混凝土板结构,分析了其在爆炸荷载作用下的抗爆性能,为今后的实际工程应用提供一定的参考。本文以有限元模拟为基础,针对所提出的防护结构进行抗爆性能研究,初步得到一些结果和结论。主要完成以下工作:（1）运用CONWEP法进行数值建模与计算,得到的结果与半经验计算公式进行分析比较,结果发现当折合比例距离Z越小,模拟的结果与半经验公式的吻合度就越差,当Z≥0.5m/6)g^1/3时,模拟结果与半经验公式基本相同,这为后续采用CONWEP法进行建模分析研究,提供了一定的依据和基础。（2）建立钢筋混凝土板有限元模型,将模拟结果与已有文献试验进行比较,验证了材料的本构模型及各参数取值的可靠性。对在爆炸荷载作用下的薄壁吸能元件进行模拟计算,结果显示波纹管有良好的吸能能力来做为耗能芯层核心元件。提出以波纹管牺牲层防护结构,在爆炸荷载作用下,与薄壁圆管牺牲层防护结构作对比,结果显示,三种结构均能有效的保护好主体结构,大大减少钢筋混凝土板的损伤,从三种结构的吸能能力及主体结构的变形损伤进一步分析,波纹管吸收能量最多,对应的主体结构变形损伤最小,在三者之中为最优。此外,对前面板厚度及波纹管厚度等因素对被保护的主体结构的影响进行了探讨。（3）提出了一种以波纹管为吸能芯层的钢筋混凝土板,为了研究爆炸载荷作用下波纹管吸能芯层钢筋混凝土板的抗爆性能和吸能机理,利用有限元软件LS-DYNA对比分析了吸能芯层分别为波纹管和直筒管的钢筋混凝土板,及同质量实心板的损伤变形和吸能特性。结果发现在相同爆炸荷载作用下,波纹管吸能芯层板背板的损伤变形均小于实心板和直筒管芯层板;波纹管吸能芯层板主要靠前面板的塑性变形及波纹管的压缩变形吸能,吸能能力要优于实心板和直筒管芯层板。波纹管吸能芯层板能有效的保护背板。此外,讨论了边界条件、炸药量、炸药点位置、前面板厚度、背板厚度、芯层波纹管的高度、厚度和数量等参数对波纹管芯层板的背板损伤变形影响规律。更多还原

【Abstract】 In recent years,terrorist attacks and accidental explosions have been increasing,this makes structural anti-explosion gain more attention,nowadays how to improve the anti-explosion performance of building structures has become one of the focus of research.Reinforced concrete slab has always been the focus of research,under explosion load,most of solid reinforced concrete slabs will produce debris due to the back tension,which will cause harm to human life.In order to reduce the damage of the explosion load on the reinforced concrete slab,the thin-wall bellows protective structure and the reinforced concrete slab with energy absorbing core are proposed in this paper,the anti-explosion performance under explosion load is analyzed,which provides some reference for practical engineering application in the future.Based on the finite element simulation,the anti-explosion performance of the protective structure is studied,and some results and conclusions are obtained.The following work is mainly completed:（1）The CONWEP method was used for numerical modeling and calculation,and the results are compared with semi-empirical formula.The results show that the smaller the proportional distance Z is,the worse the agreement between the simulated results and the semi-empirical formula is,when Z≥0.5m/kg^1/3,the simulation results are basically the same as the semi-empirical formula,it provides a certain basis for the subsequent modeling analysis and research by using CONWEP method.（2）The finite element model of reinforced concrete slab was established,and the reliability of the constitutive model and the parameters was verified by comparing the simulation results with the existing literature tests.The simulation result of the thin-walled energy absorbing elements under explosion load shows that the bellows have good energy absorbing capacity and can be used as the core elements of the energy consuming core layer.Under explosion load,the sacrificial layer protection structure with bellows as the core is proposed and compared with other sacrificial layer protection structures with straight tubes as the core,the results show that three kinds of structure can effectively protect the major structure,greatly reduce the damage of reinforced concrete slabs,from the structure of the three kinds of energy absorption ability,and further analysis of the major structure of the deformation damage,bellows absorb most energy,the corresponding major structure has the least deformation damage and is the best among the three.In addition,the influence of the thickness of front panel and bellows on the structure of the protected major structure is discussed.（3）A kind of reinforced concrete slab with bellows as energy absorbing core layer is proposed,in order to study the blast-resistant performance and energy absorption mechanism of the reinforced concrete slab of the bellow energy-absorbing core under blasting load.The finite element software LS-DYNA was used to compare and analyze the damage deformation and energy absorption characteristics of the slabs which are reinforced concrete slab with the energy-absorbing core layer of bellows,reinforced concrete slab with the energy-absorbing core layer of straight tubes and solid slab of equal quality.The results show that the damage and deformation of the back sheet of the slab with the bellow energy-absorbing core are smaller than that of the solid slab and the slab with straight tube core under the same blasting load;The slab with the bellow energy-absorbing core mainly relies on the plastic deformation of the front sheet and the compression deformation of bellows to absorb energy,and its energy absorption capacity is better than that of the solid slab and the slab with straight tube core.The slab with the bellow energy-absorbing core can effectively protect the back sheet.In addition,the effects of boundary conditions,the amount of explosive,the position of explosive point,the thickness of front panel,the thickness of back panel,the height,thickness and quantity of bellows in the core layer on the damage deformation of the back sheet are discussed.更多还原