Assessment of wind-induced nonlinear post-critical performance of bridge decks.

A quantitative analysis of the wind-induced post-critical performance of bridge decks is presented in order to highlight the underlying wind-resistant capacity after the critical wind speeds. Two simple indices, i.e., the wind speed extension (after the critical state) with acceptable post-critical vibrations and the relative post-critical capacity (i.e., the ratio between the aforementioned wind speed extension and the critical speed value), are utilized to quantify the post-critical performance of bridge decks. A short review on available limit states of vibration in literatures and design codes is presented in order to define a suitable threshold for acceptable post-critical vibrations. The post-critical performances of three typical cross-sections are quantitatively analyzed with the proposed indices, in which the limit states of vibration are reasonable defined considering either structural normal operation or structural safety. The effects of various mechanical and aerodynamic properties (e.g., mechanical damping ratio, natural frequency, initial angle of attack, and aerodynamic derivatives) on the post-critical behaviors of the selected cross-sections are highlighted. The quantitative analysis of the post-critical performance in the present work may deepen the understanding of the wind-resistant performance of bridges and potentially serve as a building block for a more economic wind-resistant design framework for future long-span bridges. • Limit states of vibration for bridge decks are briefly reviewed to define a suitable threshold for post-critical vibration. • Two simple indices are introduced to quantify post-critical performance of bridge decks. • Effects of various mechanical and aerodynamic properties on post-critical performances of three cross-sections are analyze. • The indices potentially serve as criteria in a more economic wind-resistant design framework for future long-span bridges. [ABSTRACT FROM AUTHOR]