沥青混合料抗拉性能试验研究及力学特性分析

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。

Mechanical Simulation and Experimental Research on Tensile Performance in Asphalt Mixtures

The tensile property of asphalt mixtures displays the low temperature and fatigue performance.To research the the mechanical responses and failure modes,three-dimensional nonlinear models are set up for the indirect tensile(IDT) specimen and the semi-circular bending(SCB) specimen,and the numerical analysis results are confirmed by laboratory tests.The results show that the mechanical response of IDT specimen is different from that of SCB;the dominant stress state in the SCB test is tensile stress,but the IDT specimen display a complicated stress state including compression stress,tensile stress and shear stress;in dissymmetrical state,there is a mixed stress state in IDT specimen,it may not getting tensile damage;the SCB test is better than IDT test in simulating the mechanical response of pavement.