Sanfilippo Danilo, Ghiassi Bahman, Alexiadis Alessio, Hernandez Alvaro Garcia
Department of Civil Engineering, University of Nottingham, NG7 2RD, Nottingham, UK.
School of Chemical Engineering, University of Birmingham, B15 2TT, Birmingham, UK.
Materials (Basel). 2021 Mar 24;14(7):1579. doi: 10.3390/ma14071579.
This paper demonstrates the use of peridynamics and discrete multiphysics to assess micro crack formation and propagation in asphalt at low temperatures and under freezing conditions. Three scenarios are investigated: (a) asphalt without air voids under compressive load, (b) asphalt with air voids and (c) voids filled with freezing water. The first two are computed with Peridynamics, the third with peridynamics combined with discrete multiphysics. The results show that the presence of voids changes the way cracks propagate in the material. In asphalt without voids, cracks tend to propagate at the interface between the mastic and the aggregate. In the presence of voids, they 'jump' from one void to the closest void. Water expansion is modelled by coupling Peridynamics with repulsive forces in the context of Discrete Multiphysics. Freezing water expands against the voids' internal surface, building tension in the material. A network of cracks forms in the asphalt, weakening its mechanical properties. The proposed methodology provides a computational tool for generating samples of 'digital asphalt' that can be tested to assess the asphalt properties under different operating conditions.
本文展示了运用近场动力学和离散多物理场来评估低温及冰冻条件下沥青中微裂纹的形成与扩展。研究了三种情况：(a) 无气孔的沥青在压缩载荷下；(b) 有气孔的沥青；(c) 气孔中充满冰冻水的沥青。前两种情况用近场动力学计算，第三种情况用近场动力学结合离散多物理场计算。结果表明，气孔的存在改变了裂纹在材料中的扩展方式。在无气孔的沥青中，裂纹倾向于在胶泥与集料的界面处扩展。在有气孔的情况下，裂纹从一个气孔“跳跃”到最近的气孔。在离散多物理场的背景下，通过将近场动力学与排斥力耦合来模拟水的膨胀。冰冻水对着气孔的内表面膨胀，在材料中产生张力。沥青中形成裂纹网络，削弱其力学性能。所提出的方法提供了一种计算工具，用于生成“数字沥青”样本，可对其进行测试以评估不同运行条件下的沥青性能。
