ABSTRACT

In this work, a phase field approach to modelling fracture in asphalt mixtures is presented. More specifically, a cohesive zone-based phase field model is used. The crack in the material is modelled as a regularised damage, smeared over a region of finite length, using a damage phase field variable. The damage variable takes on the value of 1 for a fully damaged surface to 0 for an intact solid. The energy dissipated due to inelastic behaviour in the damage zone is modelled using a cohesive zone concept and the associated traction-separation constitutive law. The model is implemented in a finite element framework. Several numerical examples are presented to show the performance of the model in simulating fracture in asphalt mixtures at low temperatures. Fracture under mode-I, mode-II and mixed mode is simulated. The numerical results of crack initiation and propagation agrees well with experimental observations.

摘要

在这项工作中，提出了一种模拟沥青混合料断裂的相场方法。更具体地说，使用了基于凝聚区域的相场模型。材料中的裂纹被建模为规则化损伤，使用损伤相场变量涂抹在有限长度的区域上。损坏变量的值对于完全损坏的表面为 1，对于完整的实体为 0。由于损伤区的非弹性行为而耗散的能量使用粘性区概念和相关的牵引分离本构定律建模。该模型在有限元框架中实施。给出了几个数值例子来展示该模型在模拟低温下沥青混合料断裂方面的性能。模拟Ⅰ型、Ⅱ型和混合型断裂。