Equivalent Static Wind Loads on Buildings: New Model

Abstract

In current design practice, spatiotemporally varying wind loads on buildings are modeled as equivalent static wind loads. This loading description serves as pivotal information for estimating response under the combined action of wind and other loads. This paper presents a framework for evaluating the equivalent static wind load for any given peak response of buildings with uncoupled responses in the three primary directions. A new description of the background loading based on the gust loading envelope/peak dynamic loading is presented. The resonant loading is expressed in terms of the inertial load following the respective fundamental structural mode. The equivalent static wind loading for the total peak response is then expressed as a linear combination of the background and resonant components. Following this framework, closed-form formulations using an analytical wind loading model are presented. The gust response factors and the equivalent static wind loads for various alongwind response components at different building elevations are discussed in detail highlighting the advantages of the proposed equivalent static loading. The potential high-frequency force balance technique for ascertaining the equivalent static loading on buildings is also revisited. A commentary is presented to highlight the role of mode shape correction, uncertainty in the modeling of wind loads, and contributions of higher modes to background response.