performance degradation of corrugated steel webs and concrete flange t-pbl connectors under fatigue loading

Twin perfobond shear (t-pbl) connectors are high-performance connectors; due to vehicle overloading and other problems, these connectors can undergo severe fatigue damage. to investigate the static load-bearing capabilities and performance degradation trend after the fatigue damage of the t-pbl connectors, fatigue and static tests were conducted on five full-scale t-pbl connector specimens, a fatigue life prediction method for the connectors was proposed, and a formula for calculating the residual flexural strength was established. based on the results from this study, the failure mode of t-pbl connectors with an applied static load was shear failure of the concrete tenon; the fatigue crack development occurred quickly at first and then proceeded more slowly; the greater the number of fatigue cycles and the larger load ratio correlated to more severe fatigue damage; with increasing load ratio, the residual flexural bearing capacity decreased. moreover, as the number of load cycles increased, the degradation trend followed a quadratic parabolic relationship; the residual deflection of the specimen was not significantly affected by the load ratio. after experiencing 10,000 fatigue cycles, the stiffness of the specimen increased by 2.1% to 3.5%, and following these 10,000 fatigue cycles, no significant degradation was observed in the stiffness of the specimen. fe-safe software could be used to calculate the fatigue life. based on the miner-palmgren damage theory, a calculation model for the residual flexural strength was proposed, the calculated and tested values were in good agreement, and the error was within 3%.