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.
