Parametric modeling and optimization of external braced frames for embodied energy and daylight availability

Abstract

External braced frames are structurally efficient systems used in tall building design to resist lateral load, in which the truss-based structural system is located on the perimeter of the building along the facade. One adverse consequence of an external braced frame is the obstruction of views and daylight available in the interior spaces. Daylighting is a passive design practice that utilizes daylight availability for both lighting and heating purposes to reduce building energy consumption. In this thesis, the embodied energy and daylight availability is analyzed for a 40-story building model with varying brace frame designs consisting of HSS hollow rectangular cross-sections. The parameters of the analysis include the external frame design, member density, and site location. The members of the braced frame are optimally sized based on strength and deflection requirements. The objectives include the volume of steel, the covered surface area, annual solar radiation, and the number of element connections. Consequently, the multi-objective optimization process leads to impacts on the embodied energy, operational energy, and cost of the structure. Ultimately, the main motivation for this study is to produce sustainable design solutions for tall buildings in an urban setting that are based on parallel consideration of optimization of daylight accessibility and embodied carbon.