The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
John J Blandon - One of the best experts on this subject based on the ideXlab platform.
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seismic Design forces for rigid floor diaphragms in precast concrete building structures
Journal of Structural Engineering-asce, 2007Co-Authors: Mario E Rodriguez, Jose I Restrepo, John J BlandonAbstract:Floor accelerations are needed to evaluate in-plane diaphragm forces in earthquake Resistant Design of buildings, and for the Design of their connections. Recorded floor accelerations in buildings during some past earthquakes have shown acceleration magnifications that are not properly considered by current building codes. Earthquake damage in some precast buildings seems to point out significant deficiencies in the Design of precast diaphragms. Two deficiencies stand out: the magnitude of the Design forces and the lack of suitable Design methods. This paper describes an experimental validation of a previously proposed analytical-based procedure for the evaluation of earthquake-induced floor horizontal accelerations in regular buildings built with rigid diaphragms. Horizontal floor accelerations recorded from shake table tests of four small-scale structures representing frame and frame-wall multistory reinforced concrete buildings were collected. These buildings were tested on the University of Illinois U...
Qingshan Yang - One of the best experts on this subject based on the ideXlab platform.
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wind Resistant Design and equivalent static wind load of base isolated tall building a case study
Engineering Structures, 2020Co-Authors: Zhihao Li, Guoqing Huang, Xinzhong Chen, Ying Zhou, Qingshan YangAbstract:Abstract More base-isolated tall buildings have been constructed in earthquake- and wind-prone regions in recent years. However, less work has been done on the wind-Resistant Design of base-isolated tall buildings including the Design of isolation system and the modeling of equivalent static wind load (ESWL), especially from the perspective of Chinese load code. This study presents a comprehensive investigation on the alongwind response of base-isolated tall building with a to-be-built tall building as an example. The dynamic wind loads specified in both Chinese and Japanese codes are used and compared. The influences of the stiffness and additional damping of the isolation layer on the modal characteristics of the base-isolated tall building are studied. The alongwind responses of fixed-base and base-isolated buildings are compared. The modeling of ESWL of base-isolated tall building is discussed. Finally, a parametric study is conducted to investigate the influence of the isolation layer stiffness and additional damping on the wind-induced response of the base-isolated building. A scheme of choosing the appropriate stiffness and additional damping is proposed for reducing the base shear force. These discussions and results will provide meaningful guidance to the wind-Resistant Design of base-isolated tall buildings, especially in China.
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wind induced response analysis and wind Resistant Design of hyperbolic paraboloid cable net structures
International Journal of Space Structures, 1999Co-Authors: Shizhao Shen, Qingshan YangAbstract:Cable net structures, as a kind of light and flexible structures are very sensitive to wind excitations. The wind-induced response analysis and wind-Resistant Design are studied systematically in this paper. The main subjects studied are as follows: (1) the fundamental equations of cable structures; (2) a method for displacement response analysis of cable structures; (3) the formulae for computing inner forces in cable elements; (4) the expression of dynamic coefficients for displacement and inner force of cable structures as a geometrically nonlinear system; (5) numerical parameter analysis of H. P. cable net structures and the determination of dynamic coefficients.
Mario E Rodriguez - One of the best experts on this subject based on the ideXlab platform.
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seismic Design forces for rigid floor diaphragms in precast concrete building structures
Journal of Structural Engineering-asce, 2007Co-Authors: Mario E Rodriguez, Jose I Restrepo, John J BlandonAbstract:Floor accelerations are needed to evaluate in-plane diaphragm forces in earthquake Resistant Design of buildings, and for the Design of their connections. Recorded floor accelerations in buildings during some past earthquakes have shown acceleration magnifications that are not properly considered by current building codes. Earthquake damage in some precast buildings seems to point out significant deficiencies in the Design of precast diaphragms. Two deficiencies stand out: the magnitude of the Design forces and the lack of suitable Design methods. This paper describes an experimental validation of a previously proposed analytical-based procedure for the evaluation of earthquake-induced floor horizontal accelerations in regular buildings built with rigid diaphragms. Horizontal floor accelerations recorded from shake table tests of four small-scale structures representing frame and frame-wall multistory reinforced concrete buildings were collected. These buildings were tested on the University of Illinois U...
Yukio Tamura - One of the best experts on this subject based on the ideXlab platform.
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framework for structural damping predictor models based on stick slip mechanism for use in wind Resistant Design of buildings
Journal of Wind Engineering and Industrial Aerodynamics, 2013Co-Authors: Ronwaldo Emmanuel R Aquino, Yukio TamuraAbstract:Abstract Current structural damping predictor models for buildings are based on measurements at amplitudes that are very low relative to those corresponding to wind-Resistant Design. They also assume that damping continuously increases with amplitude, or that it reaches a maximum value that is assumed to extend to wind-Resistant Design amplitude levels. However, some recent measurements at sufficiently higher amplitudes clearly show that damping could actually decrease with amplitude after reaching a maximum value. An earlier paper demonstrated the stick-slip phenomenon to describe the primary mechanism behind such increase and decrease of damping with amplitude. In the current paper, results from a study of multiple-stick-slip-component systems are further analyzed to arrive at a framework for new predictor models. Four different approaches are proposed, and are first illustrated for damping estimates of hypothetical steel buildings. Possible modifications to an existing predictor model are then demonstrated, and different estimates are discussed for one actual building. Finally, it is shown that, with the use of such a framework, the increase in wind loads would not be so significantly higher, but these are still to be considered together with higher wind load factors or recommended lower damping values that account for damping uncertainty.
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on stick slip phenomenon as primary mechanism behind structural damping in wind Resistant Design applications
Journal of Wind Engineering and Industrial Aerodynamics, 2013Co-Authors: Ronwaldo Emmanuel R Aquino, Yukio TamuraAbstract:Abstract Structural damping, particularly in wind-Resistant Design applications where the main structure is desired to generally remain within linear-elastic limits, has been widely attributed to a stick–slip mechanism occurring at material interfaces between primary structural members and secondary components. However, no one has yet proven this analytically using an appropriate mathematical model and probabilistic considerations. A theoretical expression for damping due to one stick–slip component (SSC) in a simple linear 1DOF system is thus first derived. In actual structures, there can be a very large number of SSCs, so theoretical expressions are then derived to pursue the study for a number of different cases, also considering different probability distributions to characterize the large number of unknown parameters. One apparent result from all analyses carried out is found: damping increases but eventually decreases with amplitude due to these SSCs. This amplitude dependency of structural damping can be observed in measurements on actual structures, demonstrating that the stick–slip phenomenon can indeed be a primary mechanism behind structural damping in wind-Resistant Design applications. Finally, the implication on the Design wind loads of using the derived model in contrast to current models is discussed, illustrating a limitation in these damping models.
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Experimental investigation of aerodynamic forces and wind pressures acting on tall buildings with various unconventional configurations
Journal of Wind Engineering and Industrial Aerodynamics, 2012Co-Authors: Hideyuki Tanaka, Kazuo Ohtake, Yukio Tamura, Masayoshi NakaiAbstract:Abstract Tall buildings have been traditionally Designed to be symmetric rectangular, triangular or circular in plan, in order to avoid excessive seismic-induced torsional vibrations due to eccentricity, especially in seismic-prone regions like Japan. However, recent tall building Design has been released from the spell of compulsory symmetric shape Design, and free-style Design is increasing. This is mainly due to architects’ and structural Designers’ challenging demands for novel and unconventional expressions. Another important aspect is that rather complicated sectional shapes are basically good with regard to aerodynamic properties for crosswind excitations, which are a key issue in tall-building wind-Resistant Design. A series of wind tunnel experiments have been carried out to determine aerodynamic forces and wind pressures acting on square-plan tall building models with various configurations: corner cut, setbacks, helical and so on. The results of these experiments have led to comprehensive understanding of the aerodynamic characteristics of tall buildings with various configurations.
Jose I Restrepo - One of the best experts on this subject based on the ideXlab platform.
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seismic Design forces for rigid floor diaphragms in precast concrete building structures
Journal of Structural Engineering-asce, 2007Co-Authors: Mario E Rodriguez, Jose I Restrepo, John J BlandonAbstract:Floor accelerations are needed to evaluate in-plane diaphragm forces in earthquake Resistant Design of buildings, and for the Design of their connections. Recorded floor accelerations in buildings during some past earthquakes have shown acceleration magnifications that are not properly considered by current building codes. Earthquake damage in some precast buildings seems to point out significant deficiencies in the Design of precast diaphragms. Two deficiencies stand out: the magnitude of the Design forces and the lack of suitable Design methods. This paper describes an experimental validation of a previously proposed analytical-based procedure for the evaluation of earthquake-induced floor horizontal accelerations in regular buildings built with rigid diaphragms. Horizontal floor accelerations recorded from shake table tests of four small-scale structures representing frame and frame-wall multistory reinforced concrete buildings were collected. These buildings were tested on the University of Illinois U...
