The research objective of this award is to develop an innovative life prediction and risk assessment methodology for aging bridges in cold regions. The detailed fatigue mechanism modeling, corrosive environmental effects due to deicing salts, and advanced probabilistic methods will be systematically integrated into a general framework. Fatigue damage accumulation behavior under general multiaxial random loading will be considered in this project to represent the realistic service conditions of bridges. Coupled corrosion damage growth and fatigue crack growth analysis will be used to investigate the damage interaction of steel bridges in cold regions. A rigorous uncertainty quantification and propagation analysis will be performed using random process theory and Bayesian methodology. Efficient probabilistic methods will be employed to solve the time-dependent reliability problem of bridges considering mechanical and corrosive damage accumulation.
If successful, this research will result in a detailed understanding of multi-physics damage coupling of aging bridges in cold regions. The developed methodology is general enough and will not only benefit the bridge analysis, but also benefit other types of structures, such as automobiles, aircrafts, etc. for their long term durability evaluation. A systematic multi-level educational plan is proposed to improve the undergraduate education, graduate research, and student extracurricular activities. The research methodology, tools, and results will be documented and used to enhance both undergraduate and graduate curriculum. It is expected that the success of the proposed study will significantly enhance the design, analysis and evaluation of steel bridges in cold regions. Students trained in the proposed project will play important roles in the risk management of aging bridges as many of them will be civil engineers and government employees in cold regions after their graduation.
