基于材料特性的压路机最佳速度模型与仿真

Model and simulation of roller's optimum velocity based on material characteristics

为了确定振动压路机压实速度与混合料压实效果之间的关系,基于共振理论分析处于运动状态的压路机激振器与被压材料产生共振的充分条件和必要条件;采用Burgers模型对压实过程中不同碾压阶段混合料的塑性应变和弹性应变进行研究,建立振动压路机的最佳速度数学模型,得出最佳速度与设备尺寸参数、振动参数、铺层材料特性参数及压实过程参数之间的关系;运用Matlab软件仿真分析主要参数对最佳速度的影响变化规律,得出最佳速度与被压材料铺层厚度、压路机的钢轮直径、振动频率等参数正相关曲线,最佳速度与铺层压实度、弹性模量等参数负相关曲线;以沥青路面施工中的常用设备参数(如f=45 Hz,D=1.4 m,q=50 k N/m)和典型的材料参数(如H=0.06 m,E=50 MPa)为例,在满足相对于最大理论密度的压实度为94%的规范设计要求时,确定的振动压路机最佳压实速度为4.0 km/h。

In order to determine the relationship between vibratory compaction velocity and the compaction effect of mixture, sufficient conditions and necessary conditions of resonance for the roller exciter and compacted materials in motion were analyzed on the basis of the theory of resonance; the plastic strain and elastic strain of mixture during different processes of compaction were studied for the Burgers model, the relationship between optimum velocity and the equipment size parameters, vibration parameters, material parameters, and compaction process parameters was obtained by establishing a mathematical model of optimum velocity for vibratory roller; Matlab software was used to simulate and analyse the change rules of main parameters’ influence on optimum velocity, the result indicated that the optimum velocity is positively related to layer depth of compacted materials, diameter of steel wheel, vibration frequency and so on, while negatively related to layer compactness, modulus of elasticity, ect; the common equipment parameters （such as f=45 Hz, D=1.4 m, q=50 kN/m） and the typical material parameters （such as H=0.06 m, E=50 MPa） was taken for an example, the optimum velocity of roller is identified as 4.0 km/h, conforming with 94% degree of compactness relative to the maximum theoretical density of standard design requirements.