摘要
为分析沥青路面服役期间温度疲劳损伤造成的寿命缩短,结合青藏高原的实际气候条件,在G109国道建立小型气象站,通过对实测气象数据的分析,拟合出精度较高的环境温度与热辐射日变化曲线,利用ABAQUS软件对路面结构温度场和应力场进行计算。通过计算各温度循环荷载下的耗散能分析路面损伤演化规律,以1℃/h的降温速率对TSRST试验进行模拟获得累积耗散能作为材料失效指标,建立累积耗散能与累积时间的函数关系并对温度疲劳寿命做出预测。结果如下:竖向应力较小,可忽略不计,路表对环境温度和辐射的响应最为敏感,在一个温度循环内应力状态出现两次变化;路表及沥青层底纵向应力变化曲线接近正弦函数,横向应力变化曲线接近余弦函数,且纵向拉应力普遍大于横向;随着路基深度的加深,各层峰值应力呈现减弱趋势;TSRST模拟结果累积耗散能为1 060.85 J/m^(3),路面低温期31 d累积耗散能为213.414 J/m^(3),累积损伤为0.201 17,累积耗散能与累积时间的对数具有较好的线性关系(R^(2)=0.976 87),在此环境中预测的温度疲劳寿命为3 938 h。
In order to analyze the life shortening caused by temperature fatigue damage during the service period of asphalt pavement,combined with the actual climatic conditions of the Tibetan Plateau,a small meteorological station is established on the G109 National Highway,and through the analysis of the measured meteorological data,the daily change curves of the ambient temperature and thermal radiation with high accuracy are fitted,and the temperature field and stress field of the pavement structure are calculated by using ABAQUS.The pavement damage evolution is analyzed by calculating the dissipated energy under each temperature cyclic loading,and the cumulative dissipated energy is obtained as the material failure index by simulating the TSRST experiment with a cooling rate of 1 ℃/h,establishing the functional relationship between the cumulative dissipated energy and the cumulative time and making a prediction of the temperature fatigue life.The results are as follows:the vertical stress is small and negligible,the road surface is the most sensitive to the response of ambient temperature and radiation,and the stress state changes twice in one temperature cycle;the longitudinal stress change curve of the road surface and the bottom of the asphalt layer is close to the sinusoidal function,and the transverse stress change curve is close to the cosine function,and the longitudinal tensile stress is generally larger than that of transverse direction;with the deepening of the depth of the roadbed,the peak stress in the layers shows a weakening trend;TSRST simulation results cumulative dissipation energy of 1 060.85 J/m~3,pavement low temperature period of 31 days cumulative dissipation energy 213.414 J/m~3,cumulative damage is 0.201 17,cumulative dissipation energy and the logarithm of the cumulative time has a good linear relationship(R~2=0.976 87),the predicted temperature fatigue life in this environment is 3 938 h.
作者
吕帅元
田荣燕
张旭
LYU Shuai-yuan;TIAN Rong-yan;ZHANG Xu(College of Engineering,Xizang University,Lhasa 850000,China)
出处
《公路》
北大核心
2024年第8期120-129,共10页
Highway
基金
国家自然科学基金区域创新发展联合基金项目,项目编号U21A20152-1。
关键词
沥青路面
寒区路面
耗散能
低温疲劳损伤
TSRST试验模拟
asphalt pavement
cold area road surface
dissipation can
low temperature fatigue damage
TSRST experimental simulation
