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This study investigates the complementary effects of side and corner modification strategies for the aerodynamic performance of tall buildings. A total of 81 doubly symmetric models were examined. High-frequency force balance (HFFB) wind tunnel testing was conducted at the University of Florida’s (UF) boundary layer wind tunnel (BLWT), an NSF-sponsored Natural Hazard Engineering Research Infrastructure (NHERI) Experimental Facility. The 81 models were examined under two approach flow conditions, which are suburban and open terrains. For each flow condition, the models were tested under 10 different wind angles from 0° to 45°. The base responses were recorded using a 6-axis load cell. A total of 1620 tests (81 models × 2 flow conditions × 10 wind angles) were performed in the BLWT at UF. Details are provided in the report document. 

The impact of climate change and global warming makes it imperative to seek sustainable solutions for the built environment. To facilitate the design of future sustainable buildings, wind tunnel tests are conducted in this study to investigate the flow characteristics and wind energy potential over a flat building roof with different edge configurations. Specifically, this study addresses the effect of parapet walls and roof edge-mounted solar panels on the wind flow over a flat-roof tall building. The results show that parapet walls generally slow down the wind speed and increase turbulence intensity as well as skewness angle, which compromises the efficiency of traditional turbine-based wind energy harvesting. On the other hand, the presence of solar panels on the roof edge (or on the top of the parapet wall) further alters flow separation and has the potential to enhance wind energy harvesting over the roof, especially for the solar panel inclined at 30°. In addition to providing valuable data for validating computational fluid dynamics (CFD) simulations, this study could also help to guide the design of wind energy harvesting devices on the building roof and explore the promising synergy with solar panels. 

Aerodynamic shape optimization is very useful for enhancing the performance of wind-sensitive structures. However, shape parameterization, as the first step in the pipeline of aerodynamic shape optimization, still heavily depends on empirical judgment. If not done properly, the resulting small design space may fail to cover many promising shapes, and hence hinder realizing the full potential of aerodynamic shape optimization. To this end, developing a novel shape parameterization scheme that can reflect real-world complexities while being simple enough for the subsequent optimization process is important. This study proposes a machine learning-based scheme that can automatically learn a low-dimensional latent representation of complex aerodynamic shapes for bluff-body wind-sensitive structures. The resulting latent representation (as design variables for aerodynamic shape optimization) is composed of both discrete and continuous variables, which are embedded in a hierarchy structure. In addition to being intuitive and interpretable, the mixed discrete and continuous variables with the hierarchy structure allow stakeholders to narrow the search space selectively based on their interests. As a proof-of-concept study, shape parameterization examples of tall building cross sections are used to demonstrate the promising features of the proposed scheme and guide future investigations on data-driven parameterization for aerodynamic shape optimization of wind-sensitive structures. 

This study proposes a surrogate-based cyber-physical aerodynamic shape optimization (SB-CP-ASO) approach for high-rise buildings under wind loading. Three components are developed in the SB-CP-ASO procedure: (1) an adaptive subtractive manufacturing technique, (2) a high-throughput wind tunnel testing procedure, and (3) a flexible infilling strategy. The downtime of the procedure is minimized through a parallel manufacturing and testing (llM&T) technique. An unexplored double-section setback strategy with various cross-sections and transitions positions is used to demonstrate the performance of the proposed procedure. A total of 173 physical specimens were evaluated to reach the optimization convergence within the reserved testing window. Further analysis of promising shapes considering multiple design wind speeds is suggested to achieve target performance objectives at various hazard levels. Practical information on setback and cross-section modification strategies is discussed based on the optimization results. In comparison with a square benchmark model, the roof drifts for promising candidates with similar building volumes are reduced by more than 70% at wind speeds higher than 50 m/s. This procedure is expected to provide an efficient platform between owners, architects, and structural engineers to identify ideal candidates within a defined design space for real-world applications of high-rise buildings. 

This study explores the complementary effects of side and corner modification on the aerodynamic behavior for high-rise buildings across representative design wind speeds. Twelve doubly-symmetric prismatic models were examined using high-frequency force balance (HFFB) wind tunnel testing at the University of Florida. The effectiveness of the aerodynamic strategies was quantified using roof drift and roof acceleration under different design wind speeds covering serviceability and survivability. The results show that both corner and side modifications can achieve promising aerodynamic performance under high design wind speeds. However, the effectiveness of the aerodynamic strategies is significantly reduced under low design wind speeds. With a corner modification strategy, the vortex shedding frequency is increased, leading to worse across-wind response at lower design wind speeds when compared to the square benchmark model. To address this issue, side modifications (i.e., side protrusions) can be used to preserve the vortex shedding frequency and achieve competitive aerodynamic performance while simultaneously maintaining the floor area and geometry. This research explores new aerodynamic modification options for owners, architects, and structural engineers with the aim of better aerodynamic performance for high-rise buildings without compromising other design objectives. 

Abstract Near‐fault pulse‐type ground motions have characteristics that are substantially different from ordinary far‐field ground motions. It is essential to understand the unique effects of pulse‐type ground motions on structures and include the effects in seismic design. This paper investigates the effects of near‐fault pulse‐type ground motions on the structural response of a 3‐story steel structure with nonlinear viscous dampers using the real‐time hybrid simulation (RTHS) testing method. The structure is designed for 75% of the code‐specified design base shear strength. In the RTHS, the loop of action and reaction between the experimental and numerical partitions are executed in real time, accurately capturing the velocity pulse effects of pulse‐type ground motions. A set of 10 unscaled pulse‐type ground motions at the design basis earthquake (DBE) level is used for the RTHS. The test results validated that RTHS is a viable method for experimentally investigating the complicated structural behavior of structures with rate‐dependent damping devices, and showed that the dampers are essentially effective in earthquake hazard mitigation effects involving pulse‐type ground motions. The average peak story drift ratio under the set of pulse‐type ground motions is 1.08% radians with a COV value less than 0.3, which indicated that structural system would achieve the ASCE 7–10 seismic performance objective for Occupancy Category III structures under the DBE level pulse‐type ground motions. Additionally, a nonlinear Maxwell model for the nonlinear viscous dampers is validated for future structural reliability numerical studies involving pulse‐type ground motions.