Database-Assisted Wind Load Capacity Estimates for Low-Rise Steel Frames

A comparative study is presented of the estimated wind load capacities of low-rise steel building frames based on loading patterns (magnitude and distribution) established from aerodynamic databases on the one hand, and on patterns specified in the ASCE 7 Standard on the other. The estimated capacities are based on the assumption, verified by numerous sets of calculations, and also used in the development of the ASCE 7 Standard, that the most unfavorable wind load occurs at the instant in time when the peak knee-joint bending moment is attained. The estimates are obtained from detailed inelastic finite element analyses of the frames with ultimate states associated with local and global instabilities. It is shown that the estimates based on the aerodynamic database are more realistic and risk consistent and can therefore lead to safer designs at lower costs. These estimates represent a significant advance over the ASCE 7 Standard-based estimates.