不同累积概率不平顺状态下轨道板离缝损伤研究  

Damage of track slab under different cumulative probability irregularity

作　　者：陈宪麦[1,2,3] 王日吉 徐磊 潘燕萍[1] 彭良坤 李忠 CHEN Xianmai;WANG Riji;XU Lei;PAN Yanping;PENG Liangkun;LI Zhong(School of Civil Engineering,Central South University,Changsha 410075,China;National Reserch Center of High-speed Railway Consration Technology,Changsha 410075,China;Hunan Tieyuan Civil Engineering Testing Co.,Ltd.,Central South University,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]高速铁路建造技术国家工程研究中心,湖南长沙410075 [3]中南大学湖南铁院土木工程检测有限公司,湖南长沙410075

出　　处：《铁道科学与工程学报》2023年第5期1666-1676,共11页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51478482,52008404,U1934217);中国中铁重大专项(2020-Special-02);中国科学青年人才托举工程项目(2020-2022QNRC002);湖南省自然科学基金资助项目(2021JJ30850,2022JJ20011);省部共建交通工程结构力学行为与系统安全国家重点实验室开放课题(KF2022-09);湖南铁院土木工程检测有限公司开放课题(HNTY2021K08);国铁集团实验室基础研究项目(L2022G007)。

摘　　要：为明晰线弹性模型与非线性损伤塑性模型在无砟轨道不同状态下的适用范围,研究层间离缝纵向扩展过程中轨道板在列车动荷载作用下的损伤萌生扩展规律,基于ABAQUS有限元软件建立CRTSⅠ型板式无砟轨道空间实体模型,以不同累积概率不平顺状态下的扣件支点压力作为荷载激励,分别采用线弹性模型与非线性损伤塑性模型描述轨道板混凝土应力-应变关系,对比分析整体轨道板在2种本构模型下的受力状态,分析其在轨道板-CA砂浆层层间离缝状态下的动力损伤规律。研究结果表明:在轨道结构正常状态下,各累积概率不平顺状态下的轨道板纵、横向拉应力水平较低,可采用线弹性模型简化计算;层间离缝状态下,轨道板上表面将承受较大拉应力而使轨道板受力进入塑性软化阶段,此时可采用非线性损伤塑性模型描述轨道板损伤的萌生、扩展过程。10%~90%累积概率不平顺状态下,轨道板损伤萌生所需离缝纵向长度处于820~890 mm之间,99%累积概率下仅需580 mm。轨道板损伤首先产生于第2组承轨台周围的轨下对应区域,随离缝纵向发展同时向板中与板边扩展直至贯通;轨道不平顺状态越差,轨道板损伤萌生与达到最大拉伸损伤所需离缝纵向长度越小。损伤所产生的塑性应变将引起轨道板几何状态的改变,进一步恶化轨道不平顺状态,造成轨道板损伤-轨道不平顺加剧的恶性循环。To clarify the application scope of linear elastic model and nonlinear damage plastic model in the mechanical analysis of slab track and explore the damage initiation and propagation law of track slab under the action of train dynamic load,the spatial entity model of CRTSⅠslab track was established based on ABAQUS finite element software.The fastener fulcrum forces under different cumulative probability irregularity states wer obtained as load excitation through vehicle track coupling dynamic analysis.The linear elastic model and nonlinear damage plastic model were used to describe the stress-strain relationship of track slab concrete respectively.The stress state of integral track slab under two different constitutive models was compared and analyzed,and its dynamic damage law under the separation state between track slab and CA mortar layer was studied.The results show that when the track structure is intact,the longitudinal and transverse tensile stress levels of the track slab under each cumulative probability irregularity state are low,and the linear elastic model can be used to simplify the calculation.Under the condition of interlayer separation,the upper surface of the track slab will bear large tensile stress and make the track slab enter the plastic softening stage.At this time,the nonlinear damage plastic model can be used to describe the initiation and propagation process of damage.Under the condition of 10%~90%cumulative probability irregularity,the longitudinal length of the track slab required for damage initiation is between 820~890 mm,and only 580 mm under 99%cumulative probability.The damage of track slab first occurs in the corresponding area under the rail around the second group of rail bearing platform,and extends to the middle and edge of the slab at the same time with the longitudinal development of the interlayer separation until it passes through.The worse the track irregularity is,the smaller the longitudinal length of the joint required for the damage initiation of the track slab and

关 键 词：CRTSⅠ型板式无砟轨道 层间离缝 混凝土损伤塑性模型 轨道不平顺概率模型 轨道板损伤 

分 类 号：U213.2[交通运输工程—道路与铁道工程]