Database-assisted Design and second-order effects on the wind-induced structural behavior of high-rise steel buildings

Published

October 31, 2016

Author(s)

Sejun Park, Donghun Yeo

Abstract

This work presents an investigation into second-order effects on the wind-induced structural dynamic behavior of high-rise steel structure, as considered within a Database-assisted Design (DAD) context. A geometric stiffness method that accounts for second-order effects and allows the dynamic analysis to be performed without iterations is shown to be applicable in conjunction with DAD and is used in a study of the response of a 60-story building, known as the CAARC building. Datasets of the aerodynamic pressure on the CAARC building for suburban exposure are used to calculate overturning moments and shear forces at the base, as well as members’ demand-to-capacity indexes (DCIs), inter-story drift ratios, and resultant accelerations. Dynamic analyses are performed using five reference mean hourly wind speeds at the rooftop for suburban terrain exposure (Uref = 20 m/s, 40 m/s, 60 m/s, 80 m/s, and 100 m/s). The first three and the last three wind speeds are used in analyses for serviceability and strength, respectively. The second-order effects decrease natural frequencies of vibration of the building by up to 12 %. If the resonant response is not taken into account and for Uref = 80 m/s, second-order effects increase the non-directional peak base shears by up to 9 %, the torsional moments by up to 10 %, and the overturning moments by up to 15 %. If resonance is accounted for, (i) for Uref = 100 m/s normal to a building face, the vortex shedding frequency is close to the 2nd and the 3rd natural frequencies of the building, and those effects are increased by 40 % to 56 %; for Uref = 80 m/s and a typical set of 21 structural members, the DCIs for the interaction of axial forces and bending moments, BijPM, are increased by up to 9 % for columns, 22 % for beams, and 19 % for diagonal bracings, while the DCIs for the shear forces, BijV are increased by up to 33 % for columns, 14 % for beams, and 21 % for diagonal bracings; (iii) for Uref = 60 m/s, second-order effects incre

Citation

Technical Note (NIST TN) - 1940

Report Number

1940

NIST Pub Series

Technical Note (NIST TN)

Pub Type

NIST Pubs

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DOI Link

Keywords

CAARC building, Database-Assisted Design (DAD), Demand-to-capacity index (DCI), Geometric stiffness approach, High-rise steel structures, Second-order effects, Wind effects

Citation

Park, S. and Yeo, D. (2016), Database-assisted Design and second-order effects on the wind-induced structural behavior of high-rise steel buildings, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.TN.1940 (Accessed December 12, 2024)