【作者】 王超；

【导师】 师燕超；

【作者基本信息】 天津大学 ， 土木工程， 2019， 硕士

【摘要】 近些年来,装配式结构体系被广泛使用,中建技术中心在结合国内外装配式结构体系优势的基础上,提出了一种预应力装配式混凝土框架结构新体系,并对其抗震性能进行了系统的研究。与传统的等同现浇装配式混凝土框架结构相比,预应力装配式混凝土框架结构新体系节点采用干式连接,提高了施工速度,未来将应用于学校、住宅、政府建筑等。然而,国内外恐怖袭击事件频繁发生,由于爆炸荷载作用下导致的建筑结构的连续倒塌事故时有发生,造成巨大的经济损失以及人员伤亡,因此对于预应力装配式混凝土框架结构新体系,除了需对其抗震性能进行系统研究外,还需对其在爆炸荷载作用下的动力响应及连续倒塌性能评价进行深入的研究。本文以中建技术中心提出的预应力装配式混凝土框架结构体系为研究对象,建立预应力装配式混凝土结构的有限元模型并验证模型选用材料类型以及参数的正确性,柱作为结构主要受力构件以及防连续倒塌的关键构件,为了更为准确得到预应力装配式混凝土结构柱的抗爆性能,提出合理的柱边界条件简化模型并分析影响柱抗爆性能的关键参数,在此基础上,对预应力装配式混凝土框架结构进行连续倒塌评价并分析影响其倒塌性能的关键参数,主要研究工作及研究成果如下:(1)运用ANSYS/LS-DYNA软件建立预应力装配式混凝土空间节点有限元模型,与已有试验作对比,验证模型选用材料以及参数设置的正确性。(2)根据预应力装配式混凝土框架结构的特点,提出结构柱柱顶约束刚度理论计算方法,建立了爆炸荷载作用下预应力装配式混凝土框架柱破坏分析的简化模型;基于建立的简化模型,通过参数分析研究了影响预应力装配式混凝土框架柱抗爆性能的关键因素,结果表明轴压比和混凝土强度分别对柱中残余位移和最大位移影响较大,局部箍筋加密能满足柱抗爆设计要求。(3)采用非线性动力分析方法,研究了爆炸荷载作用下预应力装配式混凝土结构平面框架结构的动力响应和抗连续倒塌性能,并与现浇结构作对比,分析两者连续倒塌机制的异同点,梁机制阶段两种结构抗力相同,悬链线机制阶段预应力装配式结构优于现浇结构。(4)在爆炸荷载作用下预应力装配式混凝土框架柱破坏分析简化模型的基础上,优化柱的竖向边界条件,建立了计算爆炸荷载下预应力装配式混凝土框架结构倒塌位移的简化模型,提出了爆炸荷载作用下预应力装配式混凝土框架结构抗倒塌性能评价方法。更多还原

【Abstract】 In recent years,assembled structure system is widely used.Based on the advantages of assembled structure system around the world,China Construction Technology Center has proposed a new system of prestressed assembled concrete frame structure,and systematically studied its seismic performance.Compared with the traditional cast-in-place fabricated concrete frame structure,the new system node of the prestressed fabricated concrete frame structure adopts dry connection,which improves the construction speed and will be applied to schools,residential buildings and government buildings in the future.However,terrorist attacks occur frequently at home and abroad,and the consecutive collapse accidents of building structures caused by explosive loads often occur,resulting in huge economic losses and casualties.Therefore,for the new system of pre-stressed assembled concrete frame structure,besides the systematic study of its seismic performance,the dynamic response under blast loads is also needed.And the performance evaluation of progressive collapse is studied in depth.This paper takes the prestressed assembled concrete frame structure system proposed by the China Construction Technology Center as the research object,establishes the finite element model of the prestressed assembled concrete structure and verifies the correctness of the material type and parameters used in the model.The column is the main force component of the structure and the key component to prevent the continuous collapse.In order to obtain the pre-stressed assembled concrete structure column more accurately.In this paper,a reasonable simplified model of column boundary conditions is proposed and the key parameters affecting the anti-explosion performance of columns are analyzed.On this basis,the continuous collapse evaluation of the pre-stressed assembled concrete frame structure is carried out and the key parameters affecting its collapse performance are analyzed.The main research work and research results are as follows:(1)The finite element model of prestressed assembly concrete space joints is established by ANSYS/LS-DYNA software.Compared with the test,the correctness of material selection and parameter setting of the model is verified.(2)According to the characteristics of the pre-stressed assembled concrete frame structure,the theoretical calculation method of restraint stiffness of the top of the column is put forward,and a simplified model for failure analysis of the pre-stressed assembled concrete frame column under explosive load is established.Based on the simplified model,the key factors affecting the anti-explosive performance of the prestressed assembled concrete frame column are studied through parameter analysis.The results show that The axial compression ratio has a great influence on the residual displacement of the column,and the strength grade of concrete has a great influence on the maximum displacement of the column.The local stirrup encryption can meet the explosion resistance design requirements of the column.(3)The dynamic response and anti-progressive collapse performance of the plane frame structure of the prestressed assembly concrete structure under blast load are studied by using the non-linear dynamic analysis method,and compared with the castin-place structure,the similarities and differences of the two progressive collapse mechanisms are analyzed.The resistance of the two structures is the same in the beam mechanism stage,and the prestressed assembly structure in the catenary mechanism stage is superior to the cast-in-place structure.(4)Based on the simplified model for failure analysis of prestressed assembly concrete frame columns under blast load and considering the boundary conditions of columns,a simplified model for calculating collapse displacement of prestressed assembly concrete frame structures under blast load is established.An evaluation method for collapse resistance of prestressed assembly concrete frame structures under blast load is proposed.更多还原