CRTSⅢ型板式轨道自适应多尺度损伤演变模型  

Adaptive multi-scale damage evolution model for CRTS Ⅲ slab track

作　　者：徐庆元[1] 孙胜伟 胡昌林 欧熙 窦祥强 XU Qingyuan;SUN Shengwei;HU Changlin;OU Xi;DOU Xiangqiang(School of Civil Engineering,Central South University,Changsha 410075,China;Zhuzhou Times New Material Technology Co.,Ltd.,Zhuzhou 412007,China;China Railway Shanghai Bureau Group Co.,Ltd.,Shanghai 200071,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]株洲时代新材料科技股份有限公司,湖南株洲412007 [3]中国铁路上海局集团有限公司,上海200071

出　　处：《铁道科学与工程学报》2024年第11期4383-4394,共12页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51978673)。

摘　　要：为解决现有宏观模型无法准确反映CRTSⅢ型板式轨道在复杂荷载下的损伤演变和全细观模型耗费大量计算资源的问题,建立一种自适应多尺度模型。该模型结合宏观梁单元、二维实体单元和混凝土细观模型3种尺度,通过损伤指标对临界区域进行识别,在计算过程中,随着损伤的逐渐加剧,梁单元会转换为二维实体单元,二维实体单元会进一步细化为表征混凝土细观特性的骨料、砂浆与界面单元,使理想化为均质材料的混凝土逐渐被非均质多相材料所取代。通过对比叠合梁模型、二维实体模型与三维实体模型的计算结果,三者应力水平差异较小,验证了梁单元转换为二维实体单元的合理性。同时,基于自适应多尺度模型对自密实混凝土的四点弯曲试验进行数值模拟,与试验结果进行对比。该模型能够以较小的自由度模拟出试件的细观断裂过程,整个过程的荷载-位移曲线吻合度较好,验证了二维实体模型细化为混凝土细观模型的合理性。将自适应多尺度模型应用于CRTSⅢ型板式轨道结构力学特性分析,以较小的自由度研究轨道结构宏观和细观力学性能,能够预测轨道结构的潜在破坏,并反映出精确的应力水平和完整的细观破坏过程。该研究模型可进一步为轨道设计和维护提供重要依据,更好地评估和优化轨道结构的性能。To solve the problems that the existing macroscopic model cannot accurately reflect the damage evolution of CRTS Ⅲ slab track under complex loading and that the full mesoscopic model consumes a lot of computational resources,an adaptive multi-scale model was established.The model combined three scales of macroscopic beam element,two-dimensional solid element,and concrete mesoscopic model,and identifies the critical region by damage index.In the calculation process,as the damage progressively intensifies,the beam element was transformed to a two-dimensional solid element,and the two-dimensional solid element was further refined to aggregate,mortar,and interface elements that characterize the microscopic characteristics of concrete.The concrete originally idealized as homogeneous material was gradually replaced by heterogeneous multiphase materials.By comparing the calculation results of composite beam model,two-dimensional solid model and threedimensional solid model,the stress level difference between the three was small,which verified the rationality of transitioning the beam element to the two-dimensional solid element.At the same time,based on the adaptive multi-scale model,the four-point bending test of self-compacting concrete was numerically simulated and compared with the test results.The model can simulate the meso-fracture process of specimen with a small degree of freedom,and the load-displacement curve of whole process was highly consistent,which verified the rationality of two-dimensional solid model refined into the concrete mesoscopic model.The adaptive multi-scale model is applied to the analysis of the mechanical properties of CRTS Ⅲ slab track structure,and the macroscopic and mesoscopic mechanical properties of track structure are studied with a small degree of freedom,which can predict the potential damage of track structure and reflect the accurate stress level and the complete meso-failure process.The research model can further provide an important basis for track design and maintenance,a

关 键 词：CRTSⅢ型板式轨道 自适应多尺度模型 宏观模型 细观模型 损伤演变 

分 类 号：U213.242[交通运输工程—道路与铁道工程]