Cohesive zone modeling of fatigue crack propagation in slab track interface under cyclic temperature load

• Published in: Engineering failure analysis Vol. 134; p. 106028
• Main Authors: Zhang, Jiawei, Zhu, Shengyang, Cai, Chengbiao, Wang, Mingze, Zhao, Hong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2022
• Subjects: Ballastless track; Double-layer concrete; Interface damage; Low-cycle fatigue; Double-layer concrete; Interface damage; Low-cycle fatigue; Ballastless track
• ISSN: 1350-6307; 1873-1961
• DOI: 10.1016/j.engfailanal.2022.106028

•A low-cycle fatigue cohesive model (LCFC) is developed for analyzing fatigue damage evolution of ballastless track interface.•The key parameters and the strain–stress relationship of track concrete interface is determined through experiment test.•The LCFC model is implemented into the interface fatigue damage analysis of ballastless track by a secondary development in software Abaqus.•The fatigue damage evolution property of ballastless track interface under extreme cyclic temperature gradient is revealed. The ballasless track has been massively applied nowadays, while the interface damage evolution of ballastless tracks is still rarely investigated. This work aims to investigate the damage evolution property of ballastless track under low-cycle fatigue load condition. The application of cyclic cohesive model as a key approach to simulated the damage evolution of ballastless track interface. Therefore, a low-cycle fatigue cohesive model (LCFC) that follows a bilinear law is established by combining and modifying existed cohesive models. The LCFC model is then implemented by a secondary development in Abaqus through implicit user-defined material subroutine (UMAT), and the validity of the model is verified though a double cantilever beam (DCB) model. To obtain the key parameters of the LCFC model for analyzing the fatigue damage of CRTS III (Chinese Railway Track System type III) ballastless track, the split tension test of specimen that is composed of the self-compacting concrete and the slab concrete is conducted, and the damage evolution process is captured through digital image correlation (DIC) technique. Further, a simulation model that involves the LCFC model is created for simulating and analyzing the interface fatigue damage of CRTS III- ballastless track under cyclic temperature gradient for the first time. The results show that the established LCFC model is suitable for studying the interface fatigue damage of CRTS III ballastless track under extreme temperature gradient cycles. The interface near the slab edge will be completely damaged within only several cycles when the cyclic temperature gradient is ± 61℃/m. The failure mode of the interface element is a kind of mixed mode failure which gradually changes from normal-dominated failure mode to shear-dominated failure mode with the increase of temperature gradient loading cycles.