Engineering Structures 28 (2006) 503–513 www.elsevier.com/locate/engstruct Wind-induced response and serviceability design optimization of tall steel buildings C.-M. Chan ∗ , J.K.L. Chui Department of Civil Engineering, Hong Kong University of Science and Technology, Kowloon, Hong Kong, China Received 3 June 2004; received in revised form 31 August 2005; accepted 3 September 2005 Available online 17 October 2005 Abstract Trends towards constructing taller and increasingly slender buildings imply that these structures are potentially more responsive to wind excitation, causing discomfort to occupants. This paper seeks to develop an integrated wind tunnel load analysis and automatic least cost design optimization procedure to assist structural engineers in the prediction of wind-induced response based on the High Frequency Force Balance (HFFB) technique and on the serviceability design of tall steel buildings. It has been shown that the wind-induced acceleration is inversely related to the natural frequency of tall buildings within the range of frequency for serviceability checking. An Optimality Criteria (OC) method is developed to minimize the structural cost of steel buildings subject to targeted frequency constraints in which the limiting frequency threshold is derived from the motion perception design criteria of ISO Standard 6897. The effectiveness of the proposed integrated wind tunnel analysis and numerical design optimization procedure is illustrated through a full-scale 45-story symmetric tubular steel building example. This building was initially found to vibrate excessively under wind loading and then the automated optimization procedure was used to determine the optimal structural stiffness satisfying the stipulated ISO Standard 6897 occupant comfort criteria. c 2005 Elsevier Ltd. All rights reserved. Keywords: Wind-induced vibration; Motion perception; Serviceability design; Structural optimization; Tall buildings 1. Introduction Recent trends towards constructing increasingly slender and taller buildings, with higher strength materials and lighter structural systems, have contributed to a new generation of wind-sensitive buildings. Very often, such slender and tall buildings experience excessive wind-induced vibration, which will cause discomfort to occupants or even shatter windows, raising concerns about serviceability design problems [1–3]. It has been widely accepted that the perception of wind-induced motion is closely related to the acceleration of buildings [1]. The wind loads on a building are very dependent on the building’s shape, height, and surroundings. Most wind codes and standards derived based on simple geometric building shapes are incapable of accurately predicting wind loads and their effects on modern buildings of unusual shapes. For the past 30 years, wind-tunnel testing has become the best practice in ∗ Corresponding author. Tel.: +852 2358 7173; fax: +852 2358 1534. E-mail address: [email protected] (C.-M. Chan). estimating wind effects on tall buildings. The High Frequency Force Balance (HFFB) technique is often used to determine the wind forces acting on buildings [4]. In this approach, a lightweight rigid model of the structure is mounted on a very stiff base balance capable of measuring aerodynamic loads over a range of incidence angles of the approaching wind. A major advantage of this approach is that wind force spectra can be measured directly while taking into account the wind buffeting caused by surrounding buildings or the terrain. Once the wind force spectra derived from the HFFB technique are obtained, they can be used to predict the lateral drift and acceleration responses analytically using the random vibration theory. As long as the geometric configuration of the building does not change, the same set of wind force spectra can be used to estimate the effects of structural design modifications without the need for further wind-tunnel tests [5]. Further details and recent advancements of various wind tunnel techniques can be referred to reference [6]. Although well-established aerodynamic and aeroelastic wind-tunnel techniques have been developed for accurate 0141-0296/$ - see front matter c 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.engstruct.2005.09.005
Wind-induced response and serviceability design optimization of tall steel buildings
Jul 01, 2023
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Related Documents
