【作者】 韩向丽；

【导师】 赵均海；

【作者基本信息】 长安大学 ， 结构工程， 2011， 硕士

【摘要】 板柱结构由于其形式简单、传力途径短捷、能充分利用净高空间并且施工方便等突出优点,迄今为止此结构已经被广泛应用于多层厂房、仓库、公共建筑的大厅等。但在一般情况下,板柱结构的节点要承受板传来的较大集中力的作用,节点抗冲切强度通常难以保证,这也是国内外研究的热点问题。由于冲切是一种无征兆的脆性破坏,所以如何提高抗冲切性能,保证其自身的延性成为这类结构开展工作的关键问题。本文应用三参数统一强度理论分别对钢筋混凝土板和无粘结预应力钢筋混凝土板的冲切性能以及相应的承载力计算方法等进行理论研究和有限元数值模拟,主要工作有：分析了常用规范关于板冲切的规定、板冲切理论研究的几种分析方法,板柱结构中的冲切破坏概念及破坏机理,结合以往文献以及板的破坏过程总结了影响板冲切的结构本身因素,为本文的理论推导提供依据。依据屈服线理论,提出了混凝土圆板和方板的抗弯承载力计算公式；利用三参数统一强度理论对钢筋混凝土板的冲切承载力进行了分析,并考虑了钢筋和板的抗弯强度对冲切承载力的影响,采用刚塑性模型,确定出轴对称条件下的冲切破坏面,推导了钢筋混凝土方板和圆板的冲切承载力计算公式；在钢筋混凝土板冲切公式的基础上,通过将有效预压应力等效为作用在板端的外力,得到无粘结预应力钢筋混凝土板的冲切承载力计算公式。应用大型有限元分析软件ANSYS,结合试验资料,对上述两种类型的板的冲切进行了数值模拟,得到不同混凝土强度、不同配筋率、不同的预应力配筋方式下板的抗冲切能力以及裂缝开展情况,证明了板中配置无粘结预应力钢筋可有效提高板的延性,与试验比较吻合,故可以应用ANSYS有限元分析软件对实际工程中的钢筋混凝土板柱结构的应力应变进行预测分析,进而指导工程实践。更多还原

【Abstract】 So far, the flat-plate structure has been widely used in multi-storey factory buildings, warehouses, the public buildings halls as many advantages. However, slab-column connections in plate structures came to bear a larger concentration from plate. Thus the connections are susceptible to punching shear failure, Since punching shear failure is a typical brittle failure, it will cause the separation of slab and column and might even cause progressive collapse of the whole structure. Many researches have been focused on this problem.In this paper, Punching shear capacities have been investigated for reinforced concrete slab and the unbonded pre-stressed reinforced concrete slab based on the three-parameter unified strength theory, The numerical models have also been established and the punching shear capacities have been simulated using finite element simulation. The main contents are listed as follows:In this paper, some common codes and the analysis methods for punching shear of the concrete plate have been reviewed firstly. The punching shear failure mechanism has been analysed. The main factors influcing the punching shear capacities have been studied according to previous literatures and the failure process.The flexural capacities for the concrete circular and square plate have been obtained based on yield line theory. The punching strength of the reinforced concrete slab is then analyzed in this paper based on the three-parameter unified strength theory. The problem is treated as a three-dimensional axisymmetrical one, the material being assumed to be rigid-plastic. The formula of the punching strength for reinforced concrete slab is derived. Based on the above work, the ultimate punching shear strength of the unbonded pre-stressed reinforced concrete slab is obtained by being equivalent the effective pre-stress to the external forces acting on the plate.The punching shear performance on the above two types of plate is simulated using the commercial finite element software ANSYS. The crack development situation and the punching shear capacities of slab are obtained. Parametric studies have been carried out to investigate the influences of concrete strength, the reinforcement ratio, different way of pre-stressed reinforcement. Good agreement can be observed by comparison with test data.更多还原