CAJ | 학술논문

为了探究沥青混合料的应力依赖性质，分别在不同应力状态及荷载频率下对一组 AC-20试件进行了动态模量试验。开发了一个包含应力依赖本构模型的用户自定义材料子程序并利用有限元模拟证实了其有效性。建立了一个典型路面结构的三维有限元模型，将沥青面层视为应力依赖性材料，而其他结构层为线弹性材料。对路面模型施加周期性荷载，并计算得到路面响应，包括动态模量的分布、路表弯沉、沥青面层的剪应力及拉应变等。试验结果及有限元模型预测值均表明了沥青混凝土的动态模量对应力状态及荷载频率具有敏感性。与线弹性模型相比，使用非线性应力依赖模型得到的预测路面响应更大；应力依赖性对路面响应的影响随着荷载频率的减小变得更加显著。
위료탐구력청혼합료적응력의뢰성질，분별재불동응력상태급하재빈솔하대일조 AC-20시건진행료동태모량시험。개발료일개포함응력의뢰본구모형적용호자정의재료자정서병이용유한원모의증실료기유효성。건립료일개전형로면결구적삼유유한원모형，장력청면층시위응력의뢰성재료，이기타결구층위선탄성재료。대로면모형시가주기성하재，병계산득도로면향응，포괄동태모량적분포、로표만침、력청면층적전응력급랍응변등。시험결과급유한원모형예측치균표명료력청혼응토적동태모량대응력상태급하재빈솔구유민감성。여선탄성모형상비，사용비선성응력의뢰모형득도적예측로면향응경대；응력의뢰성대로면향응적영향수착하재빈솔적감소변득경가현저。
In order to investigate the stress-dependent properties of hot-mix asphalt (HMA),a dynamic modulus test was conducted on a group of AC-20 specimens at various stress states and loading frequencies,respectively.A user-defined material (UMAT )subroutine incorporating stress-dependent constitutive model was developed and finite element (FE)simulation was utilized to confirm the validity of the UMAT.A three-dimensional (3D )FE model for typical pavement structure was established,considering the HMA layer as a stress-dependent material and other layers as linear elastic materials.Periodic load was applied to the pavement model and the pavement responses were calculated,including dynamic modulus distributions,surface deflection,shear stress and tensile strain in the HMA layer,etc.Both test results and FE model predictions indicate that the dynamic modulus of asphalt concrete is sensitive to stress state and loading frequency.Using the nonlinear stress-dependent model results in greater predicted pavement responses compared with the linear elastic model.It is also found that the effects of stress-dependency on pavement responses become more significant as loading frequency decreases.