Development of time-dependent elastoplastic stress-accelerated corrosion model and a simplified full-life damage evolution simulation method: Experimental and numerical studies

Abstract

This work aims at revealing the damage evolution characteristics and the deterioration law of the tensile strength of high-strength steel wires under elastoplastic stress-corrosion interaction, which is commonly encountered in bridge cables, and providing a unified model and general simulation framework for life cycle damage evolution simulation. Firstly, a custom test device was designed to apply different stress levels to the steel wires, copper-accelerated acetic-acid salt spray test was then carried out, and the three-dimensional morphology scanning and quantitative characterization of stress-accelerated-corrosion (SAC) damage were also performed after test. The corrosion damage, i.e. the mean corrosion depth, the standard deviation and coefficient of variation, were then quantified by mass loss method, and then a both time and stress-dependent damage accumulation model was developed by model construction and multidimensional nonlinear regression analysis. Secondly, a simplified SAC numerical simulation method for the full-life damage evolution was also proposed, i.e. the so called “Time/stress input-model driven-ALE updating” simulation framework, which was realized by a user defined UMESHMOTION FORTRAN subroutine embedded into ABAQUS, and provides a general method for the optimization design of operational conditions, corrosion allowance and integrity assessment of steel cable. After model calibration, a thoroughly parametric analysis was carried out on steel wire, and the characteristic of damage evolution under constant load or displacement as well as the strength degradation were revealed, and the effect of random SAC on damage evolution was also carefully studied.