热态沥青混合料路面振动压实过程ANSYS模拟研究

ANSYS RESEARCH ON VIBRATORY COMPACTING PROCESS OF HOT ASPHALT MIXTURE PAVEMENT

为研究热态沥青混合料压实过程的力学行为和变形特征,通过分析沥青混合料的振动压实机理,建立三自由度压路机非线性力学模型和运动方程,用ANSYS软件建立路面振动压实过程的力学模型。考虑混合料的变形是与率相关的应力-应变的非线性蠕变行为,运用Origin软件非线性回归来分析MTS压实试验的复杂蠕变参数,得到0.6MPa不同荷载循环下的蠕变参数值;混合料塑性流动非常显著,成为不可逆的流动变形,c1越大,蠕变越明显,塑性变形就大,c3越小,蠕变越小,塑性流动变小。结果表明:热态沥青混合料在振动冲击的作用下,塑性变形增加得很快,卸载后的永久变形使得混合料压实,形成"骨架-密实"结构;一定荷载作用次数后,混合料处于无法压实的状态。可见,混合料必须在一定的温度范围和压实功的作用下才能获得有效压实。

In order to study the mechanical behavior and deformation characteristics of a hot asphalt mixture compacting prOcess, this paper studies the vibratory compaction mechanism of asphalt mixture, and establishes three-degree-of-freedom equations of a roller nonlinear model and a mechanical model of the pavement vibratory compacting process using ANSYS software. Since mixture deformation is associated with the rate of the stress-strain behavior of nonlinear creep, this paper analyzes the complex creep parameters of the MTS compaction test using nonlinear regression of Origin software, from which the creep parameters under 0.6MPa different load cycle are obtained. The mixture plastic flow is significant and becomes irreversible deformation. A greater c1 leads to more obvious creep and greater plastic deformation, while a smaller c3 leads to smaller creep and plastic flow. The results demonstrate that the plastic deformation of hot asphalt mixture increases rapidly due to vibratory impulses, with permanent deformation making mixture compacted after unloading and form a ＇flame-dense＇ structure. The mixture is not compacted aider a certain loading times. Therefore, the mixture can only be effectively compacted under certain temperature range and compaction power.