Assessing capacity of corroded angle members in steel structures based on experiment and simulation

Abstract

The residual bearing capacity of corroded angle members is critical for safety assessment of on-service steel tower structures. In this study, a total of 90 angle members were evaluated, among which 6 angle members were un-corroded and 84 angle members, with three sizes of cross sections (L50 × 4, L56 × 4 and L70 × 5) and three slenderness ratios (L0/r = 60, 90 and 120), were corroded using an accelerated laboratory testing method. Four corrosion levels, with a mass loss ranging from 10% to 40%, were considered. The compressive capacity of these corroded angle members was evaluated. Finite element simulations were conducted to analyze the failure modes and the residual capacities of corroded angle members using the ABAQUS computer program, under the assumption of uniform corrosion of angle steel members. The test results revealed that there is a strong linear relationship between the thickness and mass losses (in percentage, %) of the corroded angle members. When the mass loss is below 43%, the residual capacity of the corroded members decreased linearly with the increasing mass loss, and the slenderness and cross section area have little influences on the residual capacity. According to the data obtained from all tests and simulations, the residual compression capacity of the angle steel members approximates to a quadratic function of their corrosion levels, as the corrosion levels ranged from 0% to 100%. The GB50017-2017 model provides a more rational prediction of the residual capacity than the ASCE10-97, DL/T5154-2012 and AISC360-05 models.