Equivalent cohesive zone modeling of the bonding performance of slab track interface with bubble defects: Theory, validation, and application

Interfacial bonding performance is critical to the long-term service of CRTS III slab tracks. However, interlayer bubble defects will deteriorate interfacial bonding performance . To estimate the effects of the interlayer bubble defects on the track structure, an axial tensile finite element model (FEM) incorporating interlayer bubble defects is established. Via the use of this model, the effects of bubble defects on the interface are analyzed. A sensitivity analysis is subsequently conducted, and a mapping relationship is developed to determine the interfacial bonding parameters. Finally, a slab track FEM is developed to analyze the effects of bubble defects on the interface within the track structure, thereby simultaneously verifying the accuracy of the mapping relationship. The results reveal that interlayer bubble defects decrease the local bonding performance, with larger bubble defects posing a higher risk of interfacial damage than smaller ones do. Additionally, the overall bonding performance is approximately linearly negatively correlated with the interfacial porosity, whereas the effect of the individual bubble area is relatively limited. Furthermore, individual bubble area intervals are restructured according to the results of sensitivity analysis, and the equivalent FEM based on the mapping relationship is verified to be efficient and accurate. Additionally, while interlayer bubble defects alone do not alter the overall damage distribution under temperature gradient loading, they increase the risk of damage initiation. These findings provide theoretical guidance for engineering evaluations of interfacial performance. • A cohesive zone modeling method incorporating bubble defects is developed. • The effect of bubble defects on interfacial bonding behavior is revealed. • A mapping relationship between bubble defects and interfacial performance is established. • The effects of bubble defects on track structures under temperature gradients are analyzed.