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| 基于三维随机细观模型的沥青混合料断裂行为研究 |
| Study on fracture behavior of asphalt mixture based on three-dimensional stochastic meso model |
| 投稿时间：2022-07-27 |
| DOI： |
| 中文关键词: 沥青混合料 三维细观模型 间接拉伸试验 内聚力模型 断裂损伤指标 |
| 英文关键词: asphalt mixture 3D meso model indirect tensile test cohesive zone model fracture damage index |
| 基金项目:国家自然科学基金资助项目(51508428,51778509). |
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| 中文摘要: |
| 为了从细观层次研究沥青混合料内部损伤失效机理,采用三维激光扫描技术获取真实集料三维形态信息,根据其形态特征参数提出一种三维随机凹凸型集料建模方法,并构建三维虚拟集料库。使用Monte Carlo方法构建AC-13三维虚拟试件,利用多刚体动力学方法模拟试件压实过程。采用截面算法获取沥青混合料二维细观模型,在模型有效性和准确性得到验证的基础上利用该模型开展虚拟间接拉伸试验,运用内聚力模型和广义Maxwell模型表征沥青混合料断裂行为和黏弹特性,引入断裂损伤指标Dm量化其内部损伤,并利用虚拟试验探讨温度对沥青混合料断裂行为的影响。结果表明,在宏观层次,主裂纹不受温度影响,沿着粗集料的边界逐渐发展直至试件破坏；在细观层次,相较于沥青内部界面单元,沥青-集料界面单元更易出现损伤,更快达到损伤失效点,且受温度影响显著。 |
| 英文摘要: |
| In order to study the internal damage failure mechanism of asphalt mixture at the mesoscopic level,the 3D morphological information of real aggregates was obtained by 3D laser scanning technology. A 3D random concave-convex aggregate modeling method was proposed according to the obtained morphological information, and a 3D virtual aggregate library was constructed. The AC-13 3D virtual specimens were constructed using the Monte Carlo method, and the compaction process of the specimens was simulated using the multi-rigid body dynamic method. Furthermore, the cross-section algorithm was used to obtain 2D mesoscopic model of asphalt mixture. After validating the effectiveness and accuracy of the model, virtual indirect tensile tests were conducted by using the model. The cohesive force model and generalized Maxwell model were used to characterize the fracture behavior and viscoelastic properties, and the fracture damage index Dm was introduced to quantify the internal damage. Additionally, the influence of temperature on the fracture behavior of asphalt mixture was investigated by virtual tests. The results show that at the macroscopic level, the main crack is not influenced by temperature and develops gradually along the boundary of coarse aggregates until the specimen is damaged. At the mesoscopic level, the asphalt-aggregate interface unit is more prone to damage and reaches the damage failure point more quickly than the asphalt internal interface unit, and it is significantly affected by temperature. |
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