Resilient Steel Frame Systems through the Use of Non-Traditional Materials

该项目旨在通过将非传统土木工程材料纳入钢结构系统，提高钢框架系统在地震荷载下的性能。目前钢框架系统的设计方法依赖于特定位置钢构件的损伤来耗散能量。在钢结构体系中使用非传统土木工程材料，如泡沫钢和蜂窝材料作为填充物，是显著降低地震对结构影响的重要手段。这些非传统材料的使用为更好地控制结构响应以及损伤的数量和位置提供了机会。因此，在极端事件发生后，修复结构和非结构损坏的需要被最小化，并保持了社区的经济完整性。这样的解决方案对于新建筑和旧钢框架系统的改造都是合理的。这项工作将为在结构设计中更广泛地使用和整合创新材料提供路线图。目前，钢框架系统通过特定构件的“保险丝”或“塑料铰链”的非弹性行为来耗散地震输入能量，限制了这些构件可使用的截面，并导致重大损坏和停机维修。该项目的具体目标是通过采用非传统材料（高阻尼橡胶，金属和聚合物泡沫，蜂窝材料）在宽法兰截面的法兰和空心结构截面的内部之间，以增加能量耗散和抑制局部屈曲，增强抗震钢框架系统的弹性和鲁棒性。为了实现这一目标，高阻尼材料在大动态循环载荷下的性能将得到表征。将对非传统土木工程材料进行力学性能试验，并进行小尺寸构件试验，考虑其在密闭填充应用中的性能。有限元模型将用于评估不同的性能和配置对中空构件的行为和耗能能力的影响。使用填充材料的梁柱连接和支撑构件的大型子组件将进行实验测试，以确定详细要求并验证屈曲缓解。非传统土木工程材料、结构工程和地震的融合也为激励下一代学生学习工程提供了机会；向大学生灌输创造性思维的必要性；并教育结构工程从业者非传统材料及其在结构中可能产生的影响。

This project aims to enhance the performance of steel frame systems under seismic loads by incorporating non-traditional civil engineering materials into steel structural systems. Current design approaches for steel frame systems rely on damage to steel members in specific locations to dissipate energy. The use of non-traditional civil engineering materials, such as steel foam and honeycomb materials as fill-in, in steel systems is an important means to significantly reduce the impact of an earthquake on a structure. The use of these non-traditional materials provides an opportunity to better control structural response and the amount and location of damage. As a result, the need to repair both structural and non-structural damage after an extreme event is minimized and the economic integrity of the community is maintained. Such solutions are plausible for both new construction and retrofit of older steel frame systems. This work will provide a road map for more extensive use and integration of innovative materials in the design of structures.Currently, steel frame systems dissipate earthquake input energy through inelastic behavior at 'fuses' or 'plastic hinges' in specified members limiting the sections that can be used for these members and leading to significant damage and downtime for repairs. The specific goal of this project is to enhance the resilience and robustness of seismic steel frame systems by employing non-traditional materials (high damping rubber, metal and polymer foams, and honeycomb materials) between the flanges of wide flange sections and the interior of hollow structural sections to increase energy dissipation and restrain local buckling. To achieve this goal, the behavior of the high damping materials will be characterized under large dynamic cyclic loads. Mechanical behavior tests will be conducted on the non-traditional civil engineering materials and small-scale member tests will consider their behavior in a confined fill application. Finite element models will be used to evaluate the effect of different properties and configurations on the behavior and energy dissipation capacity of the void-filled members. Large-scale sub-assemblies of beam-column connections and bracing members utilizing the fill materials will be experimentally tested to determine detailing requirements and verify buckling mitigation. The confluence of non-traditional civil engineering materials, structural engineering, and earthquakes also provides an opportunity to motivate the next generation of students towards engineering; impress upon university students the need to think creatively; and educate structural engineering practitioners about non-traditional materials and their possible impact in structures.