Composite Interaction of Steel Frame Members and Reinforced Concrete Walls Under Seismic Loading

9810005 Hajjar这个项目提出了一个结合计算和实验的努力，重点关注组合墙结构建筑系统中混凝土墙和钢框架构件之间界面的抗震性能。这项工作的目标是开发综合的、非线性的、静态的和动态的分析程序，用于模拟复合墙建筑结构，包括钢/混凝土界面的行为；并通过对RC墙和钢框架之间复合循环相互作用的理解来实现更多。复合结构墙体系统提供了优异的强度和刚度，可以承受服务水平的漂移和地震事件的极限力。研究的目标包括开发一种有限元公式，用于对周围有钢框架的复合钢筋混凝土墙进行地震分析，通过实验测试对嵌在混凝土板中的头钉和变形杆锚的循环剪切和抗拉强度进行量化，并对实际使用的连接件在单调和循环荷载作用下的抗剪强度和轴向强度相互作用关系进行了验证和标定。一个三维，非线性有限元模型，以模拟在钢/混凝土墙界面的循环相互作用将制定。将设计一系列的实验来记录沿RC墙和周围钢框架之间的界面的循环相互作用。该分析将采用几何和材料非线性有限元公式，对剪切连接件使用新型纤维有限元，对界面区域的混凝土使用适当的连续单元，并与混凝土和钢的应力空间塑性公式保持一致。最终目标是制定明确的指导方针：1)在组合墙系统的线性和非线性分析中纳入钢-混凝土界面行为；2)详细说明钢框架-混凝土面板连接，以达到理想的性能目标。本项目由NSF 94-154第四年竞赛项目资助。＊＊＊

9810005 Hajjar This project presents a combined computational/experimental effort focusing on the seismic behavior of the interface between concrete walls and steel frame members in composite wall structural building systems. The work targets the development of comprehensive, nonlinear, static and dynamic analysis procedures for modeling composite wall building structures, including the behavior of the steel/concrete interface; and achieving a more through understanding of the composite cyclic interaction between RC walls and steel framing. Composite structural wall systems provide excellent strength and stiffness to withstand both service level drift and ultimate forces from seismic events. The objectives of the research include the development of a finite element formulation for the seismic analysis of composite reinforced concrete walls with surrounding steel framing, the quantification through experimental testing of the combined cyclic shear and tensil strength of headed hear studs and deformed bar anchors embedded in concrete panels, and the verification and calibration of the shear and axil strength interaction relations under monotonic and cyclic loading for connectors used in practice used in practice. A three-dimensional, nonlinear finite element to model to simulate the cyclic interaction at the steel/concrete wall interface will be formulates. A series of experiments will be designed to document the cyclic interaction along the interface between RC walls and surrounding steel framing. The analyses will feature a geometrically and materially nonlinear finite element formulation, using a new fiber-based finite element for the shear connectors and appropriate continuum elements for the concrete in the interface region, align with stress-space plasticity formulations for both the concrete and steel. The ultimate goals is the development of clear guidelines for: 1) incorporating the steel-concrete interface behavior in both linear and nonlinea r analyses of composite wall systems; and 2) detailing the steel frame-concrete panel connection to achieve desirable performance goals. This project is supported under the fourth year competition of NSF 94-154. ***