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沥青混合料的抗拉性能是表征其低温与疲劳性能的重要指标。本文针对半圆弯曲试验(SCB)与劈裂试验(IDT)建立三维非线性有限元模型,对两种试验方法的受力特点与破坏模式进行数值模拟,并利用室内试验进行验证。结果表明:两试验中试件的力学响应规律明显不同;半圆弯曲试验试件主要承受拉应力,劈裂试验试件内出现压缩、拉伸、剪切多种受力模式交织现象;非轴对称受力时,劈裂试件的应力响应更为复杂,不能充分体现间接拉伸的目的。相比较而言,半圆弯曲试验更能模拟沥青混凝土路面的层底受拉状况。
Tensile properties of asphalt mixture is an important indicator of its low temperature and fatigue properties. In this paper, a three-dimensional nonlinear finite element model is established for semicircular bending test (SCB) and splitting test (IDT). The mechanical characteristics and failure modes of the two test methods are numerically simulated and verified by laboratory tests. The results show that the mechanical response of the specimens in the two tests is obviously different. The semicircular bending test specimens mainly bear tensile stress, and the splitting tensile, shear and interlacing phenomena occur in the specimen; When subjected to force, the stress response of the splitting specimen is more complicated and can not fully reflect the purpose of indirect stretching. In contrast, the semicircular bending test can simulate the tension of asphalt concrete pavement.