Experimental Investigation of the High-Temperature Performance of High-Strength Steel Suspension Bridge Wire

Abstract

Quantification of the mechanical properties of suspension bridge main cables during fire hazards is a vital part of holistic safety assessment of infrastructure. While some researchers have examined the response of main cables to thermomechanical loading, all of these studies have mentioned the limitations of their predications due to the dearth in high-temperature data for ASTM A586 high-strength wire. The wire manufacturing process produces steel with very unique microstructural properties. Due to the high degree of cold-working involved, industry standards for the high-temperature performance of structural steel framing cannot be applied to bridge wire. This article presents the results of an exhaustive experimental investigation performed to empirically characterize many aspects of the high-temperature performance of the bridge wire. In addition to the typical engineering parameters of elastic modulus, yield strength, and ultimate strength, temperature dependence of proportional limit, work-hardening coefficient, work-hardening exponent, and ultimate strain is also determined. Two temperature-dependent models of the wire stress–strain behavior are presented herein. The models represent the mean behavior of multiple tension tests at each temperature, and models far more accurate high-temperature A586 wire behavior than was previously possible.