RESEARCH ON COHESIVE ZONE MODEL OF THE INTERFACE BETWEEN CRTS Ⅱ TRACK SLAB AND CA MORTAR

Debonding between track slab and CA mortar layer is one of the main defects of CRTS Ⅱ slab-type ballastless track system. In order to describe the constitutive behavior of the interface and reveal the mechanism of debonding, an improved exponential cohesive zone model was proposed with parameters determined based on theoretical analysis and experimental data. The proposed model is a segmentation function and adopts exponential coefficients to reflect the nonlinearity of the tension-displacement relationship of the interlayer interface. It is found that: The proposed model can efficiently calculate the interface cohesive strength, the interface relative displacement at damage initiation, and the interface critical fracture energy between track slab and CA mortar, and the results are basically consistent with the experimental results. The proposed model can simulate the normal and tangential cracking behavior of the interface between track slab and CA mortar layer with relatively high accuracy.