Analysis of Deformation and Damage in Ballastless Track-bed Based on Numerical Algorithm of Cohesive Zone Model
In response to the numerical simulation of interlayer bonding in high-speed railway ballastless track-beds,a mixed-mode bilinear cohesive zone model(CZM)was derived.A numerical algorithm for the bilinear CZM under a finite element(FE)analysis framework was proposed,with its correctness being verified by comparison with the results ob-tained from FE software.Based on the proposed algorithm,an FE model of the CRTS Ⅲ type slab ballastless track-bed was built using cohesive elements to simulate the interface to analyze the structural deformation and interface damage un-der temperature gradient loads.The results show that the proposed numerical algorithm for the bilinear CZM,consistent with the calculation results of FE software,can reflect the mechanical and damage characteristics of cohesive elements under tension,shear,and tension-shear modes.Within the temperature gradient range of-50～100 ℃/m,the vertical displacement of the track-slab reaches 0.509 mm under a positive temperature gradient load,while it can reach 0.409 mm under a negative temperature gradient load.The interface damage between the track-slab and self-compacting concrete is greatly influenced by a positive temperature gradient,with damage initiation occurring at the corners of the interface and propagating towards the slab center.Local failure of interlayer bonding occurs at the temperature gradient of 97.2 ℃/m.
high-speed railwayballastless track-bedstructural deformationinterface damagebilinear cohesive zone modelnumerical algorithmtemperature gradient
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