Three-Dimensional Slab Effects in Partially-Restrained Composite Connections

9710238 Leon本项目旨在开发实验数据和分析工具，以更好地表征典型复合楼盖体系的三维效应和钢-混凝土相互作用。例如带有复合楼板的钢弯矩框架，人们对这些系统的极限强度、承载力、延性和韧性知之甚少。从基础的角度来看，研究需要回答以下问题：o外部连接在循环荷载逆转下的行为。o在循环荷载作用下连接成柱弱轴的行为。就系统强度和刚度而言，横向和重力作用之间的相互作用。o楼板对组合梁端扭约束的影响。o剪切连接程度对横向荷载作用下体系强度和刚度的影响。楼板配筋细部对力传递的影响。o抗剪螺柱在反向循环荷载作用下的性能。实验与先进的分析技术相结合，将用于解决上面描述的几个主题。实验将包括一些独特的双向加载测试，测试采用一种新型部分约束复合材料（PR-CC）连接，采用t型桩和加筋阀座。要研究的关键项目包括与柱弱轴的连接、楼板边缘的连接以及在反循环荷载下剪力柱的性能。分析组件将开发新的元素，能够有效地模拟循环荷载逆转下的复合作用。基于分量法的t型桩的实验数据和简化模型将被开发。这些连接模型以及为考虑复合作用而开发的元素将用于参数化研究，以定义具有各种PR-CC连接的结构的代码型设计规则。＊＊＊

9710238 Leon This project intends to develop experimental data and analytical tools to better characterize the three-dimensional effects and steel-concrete interaction in typical composite floor systems. Such as steel moment frames with composite floors for which very little is known about the ultimate strength capacity, ductility and toughness of these systems. From a fundamental standpoint research is needed to answer the following questions: o Behavior of exterior connections under cyclic load reversals. o Behavior of connections framing into the weak axis of columns when subjected to cyclic loads. o Interaction between lateral and gravity actions insofar as system strength and stiffness are concerned. o Effect of the floor slab on the torsional restraint at the end of composite beams. o Influence of the degree of shear connection on the strength and stiffness of the system under lateral loads. o Influence of the slab reinforcement detailing on the force transfer. o Behavior of shear studs under reversed cyclic loading. Experiments coupled with advanced analysis techniques will be used to address several of the topics described above. The experiments will include some unique bi-directional loading tests on a new type of partially-restrained composite (PR-CC) connections utilizing T-stubs and stiffened seats. Among the key items to be studies are the connections to the weak axis of the columns, connections at the edge of the floor slabs, and behavior of shear studs under reversed cyclic loads. The analytical component will develop new elements capable of efficiently modeling composite action under cyclic load reversals. Experimental data and simplified models based on the component method will be developed for T-stubs. These connection models, along with the elements developed to take into account composite action, will be used in parametric studies to define code-type design rules for structures with a wid e variety of PR-CC connections. ***