腹筋对连续深梁剪切破坏影响的有限元分析

我国现行混凝土结构设计规范关于腹筋对深梁抗剪承载力影响的考虑,主要基于简支深梁的试验数据和计算模型,相关规定对于连续深梁的适用性有待验证。腹筋对连续深梁抗剪性能的影响机理十分复杂,系统的试验研究较少,试验结果比较分散。为了弥补试验研究的不足,采用非线性有限元方法模拟钢筋混凝土连续深梁的受力性能。利用已有的试验数据,验证了基于ATENA软件建立的有限元模型,并以此为基础,对以腹筋配筋率和剪跨比为变量的64根连续深梁进行分析,研究腹筋对连续深梁受剪承载力的影响。有限元分析结果与规范公式和压杆-拉杆模型(STM)及最新提出的三参数机动法(3PKT)的比较表明,中国规范高估了水平腹筋对构件受剪承载力的贡献,STM和3PKT方法也存在各自的不足。

Finite element analysis on the effect of web reinforcement on shear failure of reinforced concrete continuous deep beams

The considerations of the effect of web reinforcement on shear strength of reinforced concrete deep beams by the current Chinese code are mainly based on the tests and models of simply supported deep beams, and their applicability to continuous beep beams remain unproven. The influence of web reinforcement on the shear mechanism is very complicated, and the systematic experiments, which lead to scattered results, are rare. In order to make up for the shortcomings of experimental analysis, nonlinear finite element method (FEM) is adopted in this paper for modeling the shear behaviour of reinforced concrete continuous deep beams. The finite element models are built up in ATENA software, and they are validated with the test results. On this basis, another 64 models beams in different web reinforcement ratios and shear span-to-depth ratios are analysed to study the influence of web reinforcement on shear strength of continuous deep beams. And the results of the finite element analysis are compared with the results from the code equation, strut-and-tie model (STM) and the recently proposed Three-Parameter Kinematics Theory (3PKT), which shows that the Chinese code overestimated the contribution of horizontal web reinforcement on the shear strength, and both STM and 3PKT have shortcomings.