CIVIL ENGINEERING 365 ALL ABOUT CIVIL ENGINEERING



The special collection on the Recent Advances in the Modeling of Wind Hazards and the Performance Assessment of Wind-Excited Systems is available in the ASCE Library (https://ascelibrary.org/jsendh/advances_modeling_wind_hazards_performance).Windstorms cause massive damage to structures and infrastructures worldwide each year. It is estimated that over $300 billion in losses have been caused by hurricanes between 2017 and 2018 in the United States alone. In addition to hurricanes, damage from severe convective storms (e.g., thunderstorms and tornadoes) rivals that of hurricanes in any given year. The engineering community has recognized that mitigation of these hazards requires advances in wind load modeling, performance and vulnerability assessment, and computational modeling of building and infrastructure systems subject to extreme winds. As such, the development of methodologies for the analysis, performance assessment, and design of structures, including residential buildings and infrastructure systems has become a very active research field in recent years. Notwithstanding this activity, the detrimental effects of windstorms on communities requires transformative breakthroughs in not only the fundamental modeling of wind loads and effects, but also methodologies that provide a means to explicitly assess the performance of wind excited systems therefore enabling the design of buildings and infrastructures with enhanced resiliency. This special collection contains 18 technical papers and highlights some of the recent advances in the fields of wind load modeling, estimation of wind effects, and performance assessment of building and infrastructure systems.Three papers in the collection focus on the computational and experimental investigation of the wind loads and profiles occurring in extreme wind events. Bhattacharyya and Dalui (2020) compare wind pressure distributions on the surface of an irregular tall building estimated from computational fluid dynamics (CFD) with two different turbulence models and specific boundary layer wind tunnel tests. Good correspondence between the two approaches is reported as is the sensitivity of the results to small aerodynamic modifications. Huang et al. (2020) presents the results of an investigation supported by experimental data on the mean wind profiles of tropical cyclones (TCs) impacting coastal China with a low-level jet feature for heights reaching 1,000 m. A quadrant-dependent TC wind profile model considering low-level jet features for estimating design wind loads on supertall buildings in coastal areas of China is proposed. Verma and Selvam (2020) outline the development of a CFD-based numerical simulator of the VorTECH experimental tornado simulator at Texas Tech University. Detailed comparisons between the numerical and experimental pressure fields are reported with focus on the vortex breakdown, touchdown, and posttouchdown phase of a tornado. The results illustrate the capability of the numerical simulator in reproducing the salient features of the VorTECH tornado simulator.A significant portion of the papers, 10 in total, have a focus on tall buildings. Aspects ranging from the development of performance-based wind engineering (PBWE) frameworks to methodologies for the nonlinear response estimation are treated. Cui and Caracoglia (2020) introduced a simulation-based PBWE framework that characterizes performance in terms of life-cycle downtime analysis estimated for performance objectives associated with occupant discomfort, failure of key equipment, and nonstructural damages to the building façade. The framework illustrates the importance of considering wind-induced inconveniences other than classic structural safety. Ouyang and Spence (2020) presented a PBWE framework that explicitly recognizes the fundamental role played by the building façade and rain hazards concurrent to extreme winds in dictating the performance of tall buildings. A simulation framework is outlined that enables the rapid estimation of repair costs and rain intrusion due to façade damage for directional hurricane climates. The study by Cheng et al. (2021) investigates the influence of building façades of tall buildings on the local wind pressures as well as the overall aerodynamic forces. The comparison is carried out considering both experimental wind tunnel and numerical CFD data. It is seen that architectural façade details can significantly influence both the local wind pressures and the aerodynamic forces. Ghaffary and Moustafa (2021) investigate through nonlinear modeling the collapse performance of a 20-story steel frame. From the results of the analysis they suggest that current code methods could lead to overly conservative designs indicating the potential for nonlinear design in practice. The study of the nonlinear response of wind excited systems was also treated in the companion papers by Bezabeh et al. (2021a, b) where the along-wind response of a special class of building system, self-centering systems, was investigated through adopting equivalent single-degree-of-freedom analysis. They show the potential of self-centering systems for achieving controlled inelastic responses and postulate their use in PBWE. Feng and Chen (2019) also investigate the use of a special system for wind engineering applications in the form of base isolation for increasing the energy dissipation capacity of tall buildings during extreme wind events. They propose an analysis framework based on statistical linearization for such systems responding in the across-wind direction. They show that a Gaussian linearization approach is able to give relatively accurate estimations. Improvements in accuracy were reported for non-Gaussian linearization. Wang and Giaralis (2021) look at the potential of using tuned mass damper inerters (TMDIs) as a means to increase energy dissipation capacity of tall buildings for frequent events. In their work they explore the effectiveness and advantages of using optimally tuned top story TMDIs and show they have potential as a strategy for reducing accelerations in the across-wind direction. The last two papers on tall buildings shift gears with Gioffrè et al. (2020) investigating strategies for reduced order modeling of elastic tall building systems subject to stochastic wind and seismic excitation while Alinejad and Kang (2020) provided an engineering review of the procedure for calculating the along-wind forces through the ASCE 7 standard.Three papers of the special collection are focused on the development and improvement of methodologies for the performance assessment of low-rise buildings. Nevill and Lombardo (2020) introduce a new scale for measuring the structural functionality of light-framed wood buildings. The scale provides a single measure for structural functionality following a damaging event, during recovery, and throughout the life of the building and can be combined with other functionality measures therefore providing estimates of total functionality. In Raji et al. (2020) the results of an experimental investigation on the propagation of wind driven rain into the interior of low-rise buildings are presented. They show that small breaches will in general lead to low wind circulation inside the building and therefore minimal wind driven rain propagation while larger breaches will lead to noticeable internal wind circulation and potential for wind driven rain propagation. Ji et al. (2020) introduces a probabilistic progressive damage model for estimating the performance of light-frame low-rise building envelopes subject to extreme winds. An approach for efficiently propagating uncertainty is outlined and successfully compared to traditional Monte Carlo methods.The last two papers of the collection are focused on the analysis of infrastructure systems other than buildings. Kim et al. (2020) present an experimental study on the effects of panel shapes on wind-induced vibrations of solar wing systems. Instability vibrations were observed for certain configurations illustrating the importance of a thorough wind analysis of these systems to prevent wind-induced damages. In the final paper of the collection, Le and Caracoglia (2020) present a theoretical framework for estimating the monetary losses associated with damages induced by tornado wind storms acting on monopole structures. The approach is framed in the setting of PBWE and life-cycle cost analysis and provides a setting that can be extended to other infrastructure systems subject to tornado winds.References Bezabeh, M. A., G. T. Bitsuamlak, and S. X. Tesfamariam. 2021a. “Nonlinear dynamic response of single-degree-of-freedom systems subjected to along-wind loads. I: Parametric study.” J. Struct. Eng. 147 (11): 04021177. https://doi.org/10.1061/(ASCE)ST.1943-541X.0003125. Bezabeh, M. A., G. T. Bitsuamlak, and S. X. Tesfamariam. 2021b. “Nonlinear dynamic response of single-degree-of-freedom systems subjected to along-wind loads. II: Implications for structural reliability.” J. Struct. Eng. 147 (11): 04021178. https://doi.org/10.1061/(ASCE)ST.1943-541X.0003124. Feng, W., and X. Chen. 2019. “Estimation of inelastic crosswind response of base-isolated tall buildings: Performance of statistical linearization approaches.” J. Struct. Eng. 145 (12): 04019161. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002465. Gioffrè, M., F. Cluni, and V. Gusella. 2020. “Characterization of an equivalent coupled flexural-torsional beam model for the analysis of tall buildings under stochastic actions.” J. Struct. Eng. 146 (11): 04020239. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002815. Huang, M., Y. Wang, and W. Lou. 2020. “Examination of typhoon-wind profiles reaching 1,000-m height over the southeast China sea based on reanalysis data set and mesoscale simulation.” J. Struct. Eng. 146 (9): 04020192. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002744. Kim, Y. C., W. Shan, Q. S. Yang, Y. Tamura, A. Yoshida, and T. Ito. 2020. “Effect of panel shapes on wind-induced vibrations of solar wing system under various wind environment.” J. Struct. Eng. 146 (6): 04020104. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002642. Ouyang, Z., and S. M. J. Spence. 2020. “A performance-based wind engineering framework for envelope systems of engineered buildings subject to directional wind and rain hazards.” J. Struct. Eng. 146 (5): 04020049. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002568. Wang, Z., and A. Giaralis. 2021. “Top-story softening for enhanced mitigation of vortex shedding-induced vibrations in wind-excited tuned mass damper inerter-equipped tall buildings.” J. Struct. Eng. 147 (1): 04020283. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002838.



Source link

Leave a Reply

Your email address will not be published.