Examining Turbulent Wind Effects on Tall Buildings
CEE Associate Professor Luca Caracoglia was awarded a $260K NSF grant for "Stochastic Approximation Algorithms for Wind-Induced Dynamics of Next-Generation Tall Buildings and Tower Structures."
Abstract Source: NSF
The progressive increment of structural complexity and sensitivity to wind-induced vibration and damage in building structures leads to the need for more accurate and more efficient methods for structural analysis and estimation of structural response. Performance-based wind engineering (PBWE) has received considerable attention in recent years, especially for the study of building structures. PBWE is necessary to advance the analysis of the next-generation, super-tall buildings and tower structures, in which a core lateral resisting system is combined with a three-dimensional system of lateral bracings through stay-cables. The three-dimensional arrangement of the stays, which may reach unprecedented lengths, makes this type of structure particularly complex. One of the technological challenges is the need for forming a cable network by connecting the stays using transverse restrainers that can reduce sensitivity to wind-induced vibration. This unique structural configuration is particularly interesting for future building construction, but the wind-induced dynamics of this configuration is not fully understood. Understanding the performance of tall structures in the setting of PBWE can lead to better structural configurations for a given set of loading conditions, consistent with desired levels of safety and affordable cost, thus promoting national welfare and prosperity. Research results will be incorporated into teaching modules at Northeastern University for an existing graduate course in wind engineering and a new special topics course on the computational mechanics of random structural systems. Project data will be archived and made publicly available in the NSF-supported Natural Hazards Engineering Research Infrastructure (NHERI) Data Depot (https://www.DesignSafe-ci.org).
This project will examine the dynamic response of tall buildings and tall towers under the effect of turbulent wind loads within the setting of PBWE. A benchmark building structure with appropriate parametric modifications of configuration will be considered. The research will explore the implementation of computationally efficient, scalable algorithms for studying the aeroelasticity of tall structures. The numerical procedures will also use state-of-the-art software for grid and cloud computing through collaboration with experts from international academic institutions and a software research company. Stochastic numerical solvers will be employed to extract natural frequencies and principal vibration modes from an initial random eigenvalue problem (with partially unknown or random properties due to structural complexity), and subsequently evaluate the wind-induced dynamic response in the frequency domain. The project will examine the structural performance under the influence of estimation errors in the aerodynamic loads and the derivation of structural fragility curves or surfaces, needed for estimation of either structural failure or loss of functionality within PBWE. Research outcomes will include the identification of key parameters characterizing safe structural operations by efficient computation of fragility (e.g., displacements and accelerations). Parametric studies will also unfold relevant details on the wind-induced dynamics of tall buildings and towers, which will assist engineers in the design of these systems.