基于加速腐蚀的起重机钢结构时变可靠性实验及应用OA

To investigate the time-dependent reliability of crane metal structures throughout their service life,Q345B steel,which is widely used,was selected as the research material.Accelerated corrosion tests were conducted using neutral salt spray test(NSS)to simulate the natural corrosion process over 0 to 60 years.Key parameters such as corrosion depth,yield strength,and fatigue life were measured under different corrosion cycles.Time-dependent models for corrosion depth,yield strength degradation,and fatigue life reduction were developed.Analysis results showed that corrosion depth follows a power-law relationship with time,while the yield strength influence coeffcient and fatigue life reduction coeffcient exhibit exponential decay patterns.Application of these models to a practical example of time-dependent reliability analysis of a 320 t/50 t bridge crane's main beam revealed the structural reliability at any given moment.The results indicated that without anti-corrosion measures,the reliability index dropped below 1.0 after 30 years of service,and the actual service life of cranes is reviewed,which provides a theoretical basis and data support for predicting the full-life-cycle reliability of crane metal structures.