Performance of CRTS-II Ballastless Track–Bridge Structural System Rebars under Fatigue Loading Test

To study the evolution of mechanical properties steel rebars in China Railway Track System Type II (CRTS II) ballastless track–bridge structural system under repeated train loads, a 1/4 scale three-span slab track simple-supported bridge specimen was manufactured and subjected to multistage fatigue test with 18 million cycles. The experimental results show that strain amplitude bar changes proportionally stress amplitude, there is an obvious increase loading stage 4, where largest. During test, cumulative strain–amplitude ratio first decreases then increases. At end increases by 5.46% 5.32%, respectively, at L/2 L/4 sections. load–strain curve rebar keeps shape oblique straight line. slope degradation 5.15% 4.81%, are enhanced three cycles: this strengthening stage. reinforcement gradually degrade from millionth cycle test: damage Finally, based on material model criterion, change rule obtained finite element simulation. simulation agree well data, proving validity calculation method proposed paper.