Safer and Greener Low-Rise Steel Structures Under Wind Loads Through Nonlinear Database-Assisted Design

Published

February 19, 2017

Author(s)

Dat Duthinh, William P. Fritz

Abstract

This paper presents an improved method for the design of steel structures that can save material and energy embodied therein while maintaining wind-resisting capacity, or substantially increase structural capacity with only modest or no increase in material consumption. The method consists of using databases of pressures measured in wind tunnel tests and applying these pressures in nonlinear structural analyses, hence the name nonlinear database-assisted design (NLDAD). Unlike earlier approaches, the approach used in this paper targets all potentially critical cross sections of the structure being designed. Improved representation of the load cases required, a more differentiated knowledge of structural response, and knowledge of ultimate capacity that was heretofore not available to structural designers, contribute to achieving more efficient use of materials, which translates into lower cost and less demand on the environment, as well as improvement in safety. NLDAD is not proposed for routine office calculations, but rather for calculations intended to develop standards provisions that reflect actual structural capacity more correctly than current methods based on linear response do. NLDAD could also be warranted for the design of industrialized buildings, due to their importance or because they are mass-produced. To illustrate the method, one frame of a steel industrial building originally designed to satisfy ASCE 7-93 wind loads was investigated. Updated ASCE 7-02 loads were used in this investigation, as well as wind tunnel measurements. Load cases were selected from the experimental database using a linear beam model. A detailed finite-element model was analyzed under the selected load cases into the large displacement, post-yielding range, with account taken of local plate buckling and initial imperfections. By using NLDAD, improvement in wind resistance of 30 % was achieved, at the cost of 3.6 % increase in weight. Most of the performance improvement was attributable to structural modifications that were partly enabled by nonlinear analysis. Conversely, a decrease in weight of the order of 10 % or even more is possible with NLDAD, with no loss of structural capacity.

Citation

Journal of Structural Engineering-Asce

Pub Type

Journals

Keywords

allowable stress, database-assisted design, finite elements, nonlinear analysis, steel structures, ultimate strength, wind loads

Citation

Duthinh, D. and Fritz, W. (2017), Safer and Greener Low-Rise Steel Structures Under Wind Loads Through Nonlinear Database-Assisted Design, Journal of Structural Engineering-Asce (Accessed April 24, 2024)