Research Initiation: 3-D Response of Reinforced Concrete Beam-Column-Slab Connections

近年来，梁柱节点与整体现浇楼板相互作用的弹塑性性能受到了广泛的关注。在多层钢筋混凝土框架结构中，由于结构变形过程中的过度损伤而导致的这种连接的不良性能会对整个结构的刚度和强度产生不利的影响。许多梁-柱-板节点作为独立试件进行了试验，并在RC试验建筑内进行了试验。拟议研究的目的是通过使用有限元方法分析一些测试连接来补充这些研究。为此，将建立一个三维材料响应模型，用于模拟混凝土在预裂阶段的行为。一个宏观的(涂抹的)混凝土开裂后本构模型将加强这一点，该模型将模拟裂纹材料的行为，包括应变软化现象以及钢筋与混凝土之间的相互作用。将进行一些参数和敏感性研究。进行这种分析的目的是为了扩大对钢筋混凝土梁-柱-板连接的内部抗力机理和极限承载力的理解。这项研究的结果也可能为未来开发能够模拟主导行为特征的简化模型提供有价值的信息，同时保持简单性和计算效率。

Recently the inelastic behavior of beam to column connections interacting with monolithically cast floor slabs has received a considerable attention. In multistory reinforced concrete (RC) frame buildings the poor performance of such connections caused by excessive damage during building deformations can adversely affect the stiffness and strength of the entire structure. A number of beam-column-slab connections have been tested as isolated specimens as well as within the RC test buildings. The objective of the proposed research is to complement such studies by analyzing a number of tested connections using the finite element method. For this purpose a 3-D material response model for simulating concrete behavior in the pre-cracked phase will be implemented. This will be augmented by a macroscopic (smeared) post-cracking constitutive model for concrete which will simulate the cracked material behavior including the strain softening phenomenon as well as the interaction between reinforcement and concrete. A number of parametric and sensitivity studies will be performed. Such analysis will be carried out with the aim of broadening the understanding of the internal load-resisting mechanisms and ultimate capacities in RC beam-column-slab connections. The results of this investigation may also produce valuable information for future development of simplified models capable of simulating the dominant behavior characteristics while retaining simplicity and computational efficiency.