摘要
无砟轨道结构在千万甚至上亿次列车荷载作用下各功能部件容易发生高周疲劳破坏,以CA砂浆为研究对象,开发疲劳损伤本构关系的材料子程序,建立损伤-有限元全耦合技术下的CRTSⅠ型板式无砟轨道CA砂浆疲劳损伤分析方法,揭示砂浆脱空、砂浆初始劣化和列车荷载变化等关键因素对无砟轨道结构部件疲劳损伤累积的影响。结果表明:全耦合方法可以反映损伤与结构应力场的相互影响机制,在一定程度上揭示了CRTSⅠ型板式无砟轨道CA砂浆层的疲劳损伤机理;CA砂浆脱空较CA砂浆初始劣化以及列车荷载变化对其损伤累积的影响突出;沿砂浆横向,随着加载次数的增加荷载应力分布逐渐均匀化;沿砂浆纵向,越靠近砂浆端部的荷载应力随着加载次数降低程度越剧烈,随着远离端部这种降低程度在迅速削弱,端部荷载应力的损失将分配到纵向其他位置的荷载应力增加,增加幅度随着远离端部逐步减少;在砂浆初始劣化50%工况中,脱空长度越长,列车荷载越大,应力的非线性变化越突出,并且在应力重分布过程中荷载应力逐步向线性化发展;在1 500万次加载范围内,应力水平小于0.5,则可以忽略CA砂浆层应力重分布对损伤累积的影响。
The functional components of the ballastless track are prone to high cycle fatigue damage, under the action of tens of millions or even hundreds of millions train loads. The material subroutine of the fatigue damage constitutive relationship for CA mortar was developed, and the fatigue damage analysis method of CA mortar layer in the CRTS Ⅰ slab track under the damage-finite element fully coupled technology was established. As a result, the influence of key factors such as mortar void, initial deterioration of mortar and train load on the accumulation of fatigue damage of slab track structural components was revealed. The research shows: the fully coupled method can reflect the interaction mechanism between the damage and the structural stress field, and the fatigue damage mechanism of the CA mortar layer in the CRTS Ⅰ slab track was revealed to a certain extent. And the mortar void of CA mortar has a more prominent effect on the damage accumulation than the initial deterioration of CA mortar and the train load. In addition, with the increase of the loading times, the load stress distribution of the transverse direction of the mortar gradually becomes uniform, while along the longitudinal direction of the mortar, the load stress closer to the end of the mortar decreases faster. As it moves away from the end, the decrease rapidly weakens, and the loss of load stress at the end will be distributed to the load stress at other longitudinal positions, and the increase will gradually decrease with the distance from the end. Besides, in the 50% initial deterioration condition of the mortar, the nonlinear change of stress becomes more prominent with the increase of void length and train load, and the load stress gradually develops linearly during the stress redistribution. When loading times less than 15 million and the stress level less than 0.5, the influence of the stress redistribution of the CA mortar layer on the damage accumulation can be ignored.
作者
邓世杰
任娟娟
杜威
章恺尧
刘伟
叶文龙
DENG Shijie;REN Juanjuan;DU Wei;ZHANG Kaiyao;LIU Wei;YE Wenlong(MOE Key Laboratory of High-speed Railway Engineering,Southwest Jiaotong University,Chengdu 610031,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;School of Traffic&Transportation Engineering,Changsha University of Science&Technology,Changsha 410114,China)
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2022年第10期103-111,共9页
Journal of the China Railway Society
基金
国家重点研发计划(2021YFF0502100)
国家自然科学基金(52022085)
青年科技创新研究团队项目(2022JDTD0015)。
关键词
CA砂浆
材料子程序
疲劳损伤
损伤-有限元全耦合方法
应力重分布
CA mortar
material subprogram
fatigue damage
damage-finite element full-couple method
stress redistribution
