摘要
以CRTSⅡ型板式无砟轨道结为基础,浇筑“轨道板-CA砂浆-支承层”(TCC)复合模型试件(100 mm×100 mm×400 mm),通过MTS万能伺服液压疲劳试验机施加弯曲疲劳荷载,采用4点弯曲试验的方法,当应力水平S为75%、85%、95%时,探讨复合模型试件的弯曲疲劳变形特性和累积损伤演化过程。研究结果表明:与普通混凝土相比复合模型试件破坏时只出现了一条主裂纹将试件完整的分开,在层与层之间的黏结处出现了水平裂纹,且试件破坏呈现显著的延性破坏特征,TCC弯曲疲劳寿命可通过S-N曲线的单对数线性关系式表达;依据材料力学的理论,分析了将试验测定的位移-荷载数据转化为应力-应变曲线方法,并推导弯曲疲劳的动弹性模量计算公式;以疲劳应变的三阶段分析基础,结合弯曲疲劳试验数据、动弹性模量计算公式、疲劳寿命的线性回归方程等,提出了基于试验结果的“轨道板-CA砂浆-支承层”复合模型试件疲劳累积损伤演化方程。
Based on the CRTSⅡ slab ballastless track structure,the track slab-CA mortar-supporting layer concrete composite(TCC)specimens(100 mm×100 mm×400mm)were cast.Upon the application of the bending fatigue load by the MTS universal servo hydraulic fatigue tester,the bending fatigue deformation characteristics and cumulative damage evolution process of composite model specimen were studied using 4-point bending test method when the stress level S was 75%,85%and 95%.The results of the study show that:compared with ordinary concrete,only one main crack appears in the composite model during its failure,which separates the specimen completely.Horizontal cracks appear at the bond between the layers,and the failure of the TCC specimens shows significant ductile failure characteristics.The TCC bending fatigue life can be expressed by the single logarithmic linear relation of S-N curve.Based on the theory of material mechanics,the method of transforming the displacement-load data measured by the experiment to the stress-strain curve was studied and the formula for calculating the dynamic elastic modulus of bending fatigue was deduced.Based on the three-stage fatigue strain analysis,the bending fatigue test data,the calculation formula of dynamic elastic modulus as well as the fatigue life of the linear regression equation,the fatigue cumulative damage evolution equation of the composite model specimen based on the test result was proposed.
作者
徐桂弘
任旭
汪权明
张志俊
吴安杰
XU Guihong;REN Xu;WANG Quanming;ZHANG Zhijun;WU Anjie(Guizhou Institute of Technology,Guiyang 550003,China)
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2021年第3期142-148,共7页
Journal of the China Railway Society
基金
国家自然科学基金(51868009,52008123)
贵州理工学院高层次人才科研启动基金(XJGC20150407)。
关键词
无砟轨道结构
TCC复合模型试件
累积损伤
ballastless track structure
TCC composite model specimen
cumulative damage
