Identification of interface mechanical behaviour of highspeed railway ballastless track using digital image correlation method
The interface damage as one of the most critical damage issues in railway slab tracks not only significantly reduce the stiffness,strength and stability of the entire track system,but also cause local buckling or longitudinal instability of the track system under complex longitu-dinal loads,and finally result in serious safety problems of high-speed trains.In this work,the normal and shear interface cracking experiments on the interface-bonded components from double-block ballastless track were carried out,and the full-field evolution of strain distribution of the specimen under monotonic splitting loading is obtained using computer vision-based data analysis procedure,digital image correlation(DIC)technique,and the key parameters of a cohesive zone model for describing the interface stress-displacement relationship is determined.Furthermore,to elucidate the practical application of the proposed models,the interface damage evolution of the double-block ballastless track under temperature gradient loads are investigated based on the cohesive zone model.Results show that the DIC technique can well describe the entire process from the interface damage development,crack initiation and propagation to complete failure of the double-block ballastless track.It offers the advantage of providing spatially continuous measurements of displacements and a full-field strains when compared with conventional techniques.The key parameters of the cohesive zone model can be conservatively selected with the interface bonding strength of 1.05MPa,the corresponding displacement of 1.11μm,and the critical fracture energy of 3.26J/m2 in the normal direction.Much attentions should be paid to the negative temperature gradient load of larger than-60℃/m which can cause initiation of interface cracks.
Computer vison digital image correlation technique ballastless track interface damage cohesive zone model
S.Zhu W.Zhai C.Cai
Train and Track Research Institute,State Key Laboratory of Traction Power,Southwest Jiaotong University,Chengdu,P.R.China
国际会议
The 7th World Conference on Structural Control and Monitoring(7WCSCM)(第七届结构控制与监测世界大会)
青岛
英文
1585-1595
2018-07-22（万方平台首次上网日期，不代表论文的发表时间）