沥青混合料动态弹性模量场模型的建立与应用

为获得能表征不同工况下沥青混合料力学性能的本构方程,采用沥青混合料标准马歇尔试件的单轴压缩试验数据,获得以加载速率和应力状态为自变量的动态弹性模量场模型.基于ABAQUS/VUMAT编写了材料本构的用户子程序,依据试验数据分析了模型的可靠性.分别采用沥青混合料劈裂试验中压头的竖向位移数据和沥青混合料小梁弯拉试验中的弯拉强度数据验证动态弹性模量场模型在不同工况下的通用性.结果表明:采用动态弹性模量场模型的计算结果与不同加载速率下沥青混合料的单轴压缩、劈裂和小梁弯曲等工况下的试验数据吻合较好.动态弹性模量场模型能描述沥青混合料材料参数与受力状态和加载历史的依赖性,可为复杂受力状态下沥青混合料结构的力学分析提供一种方法.

Establishment and Application of Dynamic Elastic Modulus Field Model for Asphalt Mixtures

In order to characterize mechanical properties of asphalt mixture under different working conditions, a constitutive equation called dynamic elastic modulus field model was proposed. The dynamic elastic modulus field model, which was obtained by using uniaxial compression test data of standard Marshall specimens, was established with the loading rate and stress state as independent variables. A user subroutine for the model was written by ABAQUS/VUMAT and verified by other experimental data. Vertical displacement data of pressure head in asphalt mixture splitting test and flexural tensile strength data in asphalt mixture bending test were respectively applied to verify the generality of dynamic elastic modulus field model in different conditions. The results show that calculation results using dynamic elastic modulus field model are in good agreement with test data of uniaxial compression, splitting and bending under different loading rates individually. The dynamic elastic modulus field model can describe material parameters dependences for asphalt mixture on stress state and load history and provide a new way to analyze asphalt mixture under complex structure shapes and stress states.