Seismic Design of RCS Frame Connections for Repairable Damage

9710204鬼魂该研究项目将调查组合(钢-混凝土)结构中外部框架连接的地震反应，重点是定义“可修复损伤”的极限状态，并调查组合连接标准修复方法的有效性。目前，这种连接件正在承受不断增加的位移幅度的反向循环荷载，最终达到与大约5%的层间位移相对应的位移水平。这一层间漂移程度超出了“生命安全”的极限状态，近似处于“防止倒塌”的极限状态。将对六个待修复的试件中的大约四个进行重新测试，并将建造另外两个RCS外部连接，其设计与其中两个原始试件的设计类似，以进行重新测试。这些试件将承受不断增大的位移的反复荷载作用，在层间位移水平停止试验应低于“生命安全”极限状态，但超过“即刻占用”极限状态。试验后的分析研究将用于模拟在其原始行为和修复行为期间测量的RCS连接行为。将比较所有试件在不同层间漂移水平下的刚度和强度保持程度以及耗能能力，特别是对相同连接在“原始”和“修复”状态下的结果进行比较。分析模型将被开发用于RCS框架结构的试验设计。分析模型和试验设计将与美国目前在其他美国大学和日本研究机构的RCS框架研究项目进行协调。这是一个由NSF第94-154号倡议“复合材料和混合结构”支持的项目。***

9710204 Wight The research project will investigate the seismic response of exterior frame connections in composite (steel-concrete) structures, with emphasis on defining a "repairable damage" limit state and investigating the effectiveness of standard repair methods for composite connections. Currently such connection subassemblies are being subjected to reversed cyclic loading of increasing displacement magnitudes, eventually reaching displacement levels corresponding to approximately 5% interstory drift. This degree of interstory drift is beyond the "life safety" limit state and approximately at the "collapse prevention" limit state. Approximately four of the six specimens for repair will be retested and two additional RCS exterior connections with designs similar to two of the original specimens will be constructed for retesting. These specimens will be subjected to reversed cyclic loading to increasing displacements, stopping the testing at interstory drift level should be below the "life safety" limit state, but beyond the "immediate occupancy" limit state. Post-test analytical studies will be used to simulate the measured RCS connection behavior during both its original and repaired behavior. The degree of stiffness and strength retention, and amount of energy dissipation capacity at various interstory drift levels, will be compared between all specimens, with special emphasis on the comparison of the results for the same connection in its "original" and "repaired" conditions. Analytical models will be developed for use in trial designs of RCS frames structures. The analytical modeling and trial designs will be coordinated with current U.S. research projects on RCS frames at other U.S. universities and Japanese research institutions. This is a project supported under the NSF initiative No. 94-154 "Composite and Hybrid Structures". ***