摘要
基于虚拟裂纹闭合法(VCCT)以及广义Paris公式,对隧道复合式路面的疲劳裂纹扩展寿命进行研究。首先对现有的虚拟裂纹闭合法进行改进,编写出能够模拟复合式路面疲劳裂纹扩展的子程序UEL;采用有限元软件Abaqus对子程序UEL进行调用,计算出路面结构的能量释放率以及应力强度因子,结合广义Paris公式求得其疲劳裂纹扩展寿命。改进的虚拟裂纹闭合法能以一个模型计算出多种裂纹长度对应的能量释放率,很大程度上降低了计算代价;数值模拟结果表明:Ⅰ型应力强度因子KⅠ随着裂纹扩展长度的增加而增大;Ⅱ型应力强度因子KⅡ随着裂纹长度增加先呈递减趋势,然后递增;有效应力强度因子K eff与Ⅱ型应力强度因子KⅡ的变化规律大致相同。还利用改进后的虚拟裂纹闭合法研究了上下面层模量、混凝土层模量以及超载对疲劳裂纹扩展寿命的影响。结果表明:超载系数的增大会使复合式路面的疲劳裂纹扩展寿命显著降低;疲劳裂纹扩展寿命会随着上下面层模量的增大而递增,并与上下面层模量呈近似线性关系;疲劳裂纹扩展寿命也会随着混凝土层模量的增大而递增,但递增速率会逐渐变缓。对路面疲劳寿命影响大小的次序为:超载系数>混凝土模量>下面层模量>上面层模量。研究结果对复合式路面的结构设计具有一定的参考价值。
Based on the virtual crack closure method(VCCT)and the generalized Paris formula,the fatigue crack propagation life of tunnel composite pavement was studied.Firstly,the existing virtual crack closure method was improved and a subroutine UEL that could simulate the fatigue crack propagation of composite pavement was developed.Using the finite element software Abaqus,the subroutine UEL was called to calculate the energy release rate and stress intensity factor of the pavement structure,and the fatigue crack propagation life was obtained by combining with the generalized Paris formula.The improved virtual crack closure method could calculate the energy release rate corresponding to various crack lengths in one model,which greatly reduced the computational cost.The numerical simulation results show that the type I stress intensity factor KⅠincreases with the crack propagation length.With the increase of the crack length,type II stress intensity factor KⅡfirst decreases,then increases.The effective stress intensity factor K eff and the type II stress intensity factor KⅡchange roughly the same.By use of the improved virtual crack closure method,the effects of upper and lower layer modulus,concrete layer modulus and overload on fatigue crack propagation life were studied.The results show that the increase of the overload coefficient will significantly reduce the fatigue crack propagation life of the composite pavement;the fatigue crack propagation life will increase with the increase of the upper and lower layer modulus,which is approximately linear with the upper and lower layer modulus.The fatigue crack propagation life will also increase as the modulus of the concrete layer increases,but the increase rate will gradually slow down.The order of influence on the fatigue life of the road surface is:the overload coefficient>the concrete modulus>the underlying layer modulus>the upper layer modulus.The research results have certain reference value for the structural design of composite pavement.
作者
孔令云
邹胜楠
黄麟钬
吴海鹰
余苗
杨博
KONG Lingyun;ZOU Shengnan;HUANG Linhuo;WU Haiying;YU Miao;YANG Bo(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Chongqing Jiaotong University Engineering Design Institute Co.,Ltd.,Chongqing 400074,China;CMCU Engineering Co.,Ltd.,Chongqing 400039,China)
出处
《重庆交通大学学报（自然科学版）》
CAS
CSCD
北大核心
2021年第4期91-97,126,共8页
Journal of Chongqing Jiaotong University(Natural Science)
基金
国家自然科学基金项目(51708071)
浙江省交通运输厅科技计划项目(2018037)。
关键词
道路工程
复合式路面
疲劳裂纹扩展寿命
虚拟裂纹闭合法
广义Paris公式
超载系数
highway engineering
composite pavement
fatigue crack propagation life
virtual crack closure technique
generalized Paris formula
overload coefficient
