客货共线铁路CRTSⅠ型板式无砟轨道疲劳寿命预测
|
摘要
针对客货共线铁路CRTSⅠ型板式无砟轨道的疲劳寿命问题,采用有限元软件,通过应力等效原理及列车运行速度确定了室内混凝土疲劳试验的加载值和加载频率;在各组合工况下对混凝土试件进行重复加载,分析了抗折强度和动弹性模量的关系,确定采用动弹性模量衰减幅值来评价混凝土疲劳寿命;将试验结果拟合为混凝土损伤曲线,并基于Palmgren-Miner疲劳累积伤损准则得到不同荷载作用下轨道板疲劳寿命预测值。结果表明:混凝土动弹性模量和抗折强度之间存在良好的相关性;荷载频率越低或应力水平越高,混凝土损伤发展速度越快;忽略其他荷载耦合作用时,客车荷载作用下轨道板的疲劳寿命约为货车荷载作用下的2倍,而客、货车荷载交替作用下无砟轨道的疲劳寿命则介于上述2种荷载作用之间。
Aiming at the fatigue life problem of CRTS I slab ballastless track in mixed passenger and freight railway,the loading value and the frequency of indoors concrete fatigue test were determined through stress equivalence principle and train speed by using finite element software.Concrete specimens were repeatedly loaded under various combined working conditions,and the relationship between flexural strength and dynamic elastic modulus was analyzed,so as to determine that fatigue life of concrete could be evaluate by the attenuation amplitude of dynamic elastic modulus.The test data were fitted to concrete damage curve, and the predicted value of fatigue life of track slab under different loads were obtained based on Palmgren-Miner rule.The results reveal that there is a good correlation between the dynamic elastic modulus and flexural strength of concrete.The lower load frequency or the higher stress level would lead to accelerated damage evolution of concrete.Moreover,the fatigue life of track slab under passenger train load is about 2 times of that under freight train load,and the fatigue life under the alternating effects of passenger train and freight train is between above two,when neglecting the coupling effects of other factors.
Aiming at the fatigue life problem of CRTS I slab ballastless track in mixed passenger and freight railway,the loading value and the frequency of indoors concrete fatigue test were determined through stress equivalence principle and train speed by using finite element software.Concrete specimens were repeatedly loaded under various combined working conditions,and the relationship between flexural strength and dynamic elastic modulus was analyzed,so as to determine that fatigue life of concrete could be evaluate by the attenuation amplitude of dynamic elastic modulus.The test data were fitted to concrete damage curve, and the predicted value of fatigue life of track slab under different loads were obtained based on Palmgren-Miner rule.The results reveal that there is a good correlation between the dynamic elastic modulus and flexural strength of concrete.The lower load frequency or the higher stress level would lead to accelerated damage evolution of concrete.Moreover,the fatigue life of track slab under passenger train load is about 2 times of that under freight train load,and the fatigue life under the alternating effects of passenger train and freight train is between above two,when neglecting the coupling effects of other factors.
引文
[1]王智猛,蒋关鲁,李华明,等.遂渝线无砟轨道道岔区基床动力测试研究[J].铁道建筑,2008,48(10):84-87.
[2]孟宪宏.混凝土疲劳剩余强度试验及理论研究[D].大连:大连理工大学,2006.
[3]庞林飞.钢筋混凝土板疲劳损伤识别及疲劳寿命预测[D].南京:东南大学,2004.
[4]杨培冰.冻融循环作用下预应力混凝土梁疲劳特性研究[D].郑州:郑州大学,2017.
[5]余红发,孙伟,麻海燕,等.基于损伤演化方程的混凝土寿命预测方法[J].建筑科学与工程学报,2012,29(1):1-7.
[6]卫军,周之津,赵永义,等.实用路面混凝土抗折强度的无损检测方法[J].郑州工学院学报,1992,13(3):32-39.
[7]张敏.用无破损方法检测混凝土路面抗折强度[J].公路交通科技,1993(10):11-14.
[8]骆静静.硫酸盐、氯盐和弯曲荷载作用下混凝土损伤研究[D].扬州:扬州大学,2012.
[9]余红发,孙伟.在冻融或腐蚀环境下混凝土使用寿命预测方法Ⅰ:损伤演化方程与损伤失效模式[J].硅酸盐学报,2008,36(3):132-133.
[10]何燕平.CRTSⅢ型板式无砟轨道疲劳特性研究[D].成都:西南交通大学,2011.
[2]孟宪宏.混凝土疲劳剩余强度试验及理论研究[D].大连:大连理工大学,2006.
[3]庞林飞.钢筋混凝土板疲劳损伤识别及疲劳寿命预测[D].南京:东南大学,2004.
[4]杨培冰.冻融循环作用下预应力混凝土梁疲劳特性研究[D].郑州:郑州大学,2017.
[5]余红发,孙伟,麻海燕,等.基于损伤演化方程的混凝土寿命预测方法[J].建筑科学与工程学报,2012,29(1):1-7.
[6]卫军,周之津,赵永义,等.实用路面混凝土抗折强度的无损检测方法[J].郑州工学院学报,1992,13(3):32-39.
[7]张敏.用无破损方法检测混凝土路面抗折强度[J].公路交通科技,1993(10):11-14.
[8]骆静静.硫酸盐、氯盐和弯曲荷载作用下混凝土损伤研究[D].扬州:扬州大学,2012.
[9]余红发,孙伟.在冻融或腐蚀环境下混凝土使用寿命预测方法Ⅰ:损伤演化方程与损伤失效模式[J].硅酸盐学报,2008,36(3):132-133.
[10]何燕平.CRTSⅢ型板式无砟轨道疲劳特性研究[D].成都:西南交通大学,2011.