Discrete element modeling to predict the modulus of asphalt concrete mixtures
Discrete element modeling to predict the modulus of asphalt concrete mixtures
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DOI：
10.1061/(asce)0899-1561(2004)16:2(140
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发表时间：
2004-03-01
影响因子：
3.2
通讯作者：
Buttlar, WG
中科院分区：
文献类型：
--
作者：
You, Z;Buttlar, WG
本文使用微织物离散元件建模（MDEM）方法来预测在测试温度和载荷频率的范围内的沥青混合物在拉伸/压缩中的复合模量。该方法允许采用各种本构模型来描述颗粒和界面特性，如法向和剪切刚度和强度。开发了一个未校准的二维（2-D）模型，并将复模量预测值与模量的理论界限进行了比较。正如预期的那样，未校准的2-D模型低估了粗骨料骨架结构的显着硬化效应，并且发现预测接近理论下限，远低于实验确定的模量。开发了一种技术，通过扩张骨料以创建额外的骨料接触来将MDEM模型校准到实验结果，这被认为更能代表实际的三维行为。这种方法被证明提供更好的模量估计在一系列的测试温度和负载频率相比，更传统的校准方法。随着未来建模工作扩展到三维，所需的模型校准程度应大大降低。
The microfabric discrete element modeling (MDEM) approach is used herein to predict the asphalt mixture complex modulus in extension/compression across a range of test temperatures and load frequencies. The method allows various constitutive models to be employed to describe particle and interface properties, such as normal and shear stiffness and strength. An uncalibrated two-dimensional (2-D) model was developed, and complex modulus predictions were compared to theoretical bounds on moduli. As expected, the uncalibrated 2-D model underestimates the significant stiffening effects of the coarse aggregate skeletal structure and predictions are found to be near the lower theoretical bounds, well below experimentally determined moduli. A technique was developed to calibrate the MDEM model to experimental results by dilating aggregates to create additional aggregate contact, which is believed to be more representative of the actual three-dimensional behavior. This method is shown to provide better modulus estimates across a range of test temperatures and load frequencies compared to more traditional calibration methods. As future modeling efforts are extended to three dimensions, the degree of model calibration required should be greatly reduced.