基于有限元分析的沥青路面自振频率研究

利用Abaqus有限元软件建立三维沥青路面结构模型,对沥青路面结构的自振频率进行研究,并采用现场实测与室内试验验证该模型的合理性。以半刚性基层沥青路面为重点,对不同路基路面结构参数进行敏感性分析。结果表明：模型与实测数据之间的误差约为7%,模型合理;典型的半刚性基层沥青路面的自振频率一般在10～20Hz之间;面层和基层的模量变化对沥青路面的自振频率基本无影响,但随着它们厚度的增加,基频有减小趋势,厚度每增加5cm基频减小0.2Hz左右,第2～10阶的自振频率无变化;基频随着垫层模量的增加呈小幅度增加,而随着厚度的增加基频减小,厚度每增加5cm基频减小0.2Hz左右,第2～10阶的自振频率不受结构组合的影响;路基模量对沥青路面的自振频率影响较大,基频和第2～10阶的自振频率均随路基模量的增加而增加,增量2～3Hz/10MPa之间,且路基模量增加时,第2～10阶的自振频率增量比基频增量大0.6Hz左右。

Natural Frequency of Asphalt Pavement Via Finite Element Analysis

This paper presents the study of natural frequency of asphalt pavement structure by using Abaqus in a three-dimensional model.Field measurement and laboratory test are used to prove the consistency of this model,and sensitivity of subgrade and pavement＇s structure parameters are analyzed by using semi-rigid asphalt pavement as an example.The results show that the difference between the model and measured data is within 15%,thus the model is reliable;the value of natural frequency of typical asphalt pavement with semi-rigid base is between 15Hz and 20Hz.Furthermore,the changes of the surface and base＇s modulus have no effect on asphalt pavement＇s natural frequency.However,the first-order frequency decreases with addition of their thickness while frequency from 2 to 10 steps has no difference.With the increasing of subbase modulus,there is a little increase of first-order frequency.However,when the subbase gets thicker,the first-order frequency will decrease,about 0.2Hz per 5cm and the 2 to 10 steps natural frequency does not change with structural combination.Subgrade has great impact on the natural frequency,as the frequency increases with the increasing of subgrade modulus,about 2Hz/10Mpa to 3Hz/10Mpa,and when subgrade modulus increases,the frequency from 2 to 10 steps is about 0.6Hz bigger than the first-order frequency.