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为了提高沥青摊铺机的压实效率,获得高密实摊铺效果,针对摊铺机振动熨平板与摊铺材料组成的阻尼受迫振动系统,通过两者之间相互作用机理分析和动力学研究,得出共振区与频率比、阻尼比之间的关系。基于共振理论对“机械-材料”系统建立了铺层材料密实度与振动参数、系统参数之间关系的仿真模型,得到材料的摊铺密实度与熨平板频率变化特性曲线,通过对不同混合料的模型分析确定了最佳振动频率及有效频率范围,同时对2类典型的混合料SMA-13和AC-20摊铺密实度的频率特性进行了仿真计算和足尺试验验证。结果表明:4.75mm筛孔通过率为24.3%、沥青用量(质量分数,下文同)为6.37%的间断级配混合料SMA-13最佳振动频率为30 Hz;4.75mm筛孔通过率为40.3%、沥青用量为4.31%的连续级配混合料AC-20最佳振动频率为35 Hz;随着混合料中沥青含量的增加,粗集料比例增大,最佳激振频率减小;仿真计算结果与试验结果变化规律基本一致;当激振频率大于75%最佳振动频率时对混合料有高效压实效果,该研究结果可为沥青混合料的高效压实提供依据。
In order to improve the compacting efficiency of asphalt paver and get the high density paving effect, the damped forced vibration system composed of the vibration screed and the paving material of the paver is analyzed through the mechanism of interaction and kinetics , Get the resonance zone and the frequency ratio, damping ratio between the relationship. Based on the resonance theory, a simulation model of the relationship between the densification and vibration parameters and the system parameters of the ply material was established for the “mechanical-material” system. The curves of the paving density and screed frequency variation were obtained. The model analysis of the mixture determines the optimum vibration frequency and effective frequency range. Simultaneously, the frequency characteristics of two typical mixed materials, SMA-13 and AC-20, are simulated and verified by full-scale test. The results showed that the best vibration frequency of discontinuous compound SMA-13 with frequency of 4.75mm was 24.3%, asphalt content (mass fraction, hereinafter the same) was 6.37%, and the pass frequency of 4.75mm was 40.3 %, Asphalt content of 4.31% of the continuous grading mixture AC-20 optimum vibration frequency of 35 Hz; with the asphalt content of the mixture increases, the proportion of coarse aggregate increases, the optimal excitation frequency decreases; Simulation The calculated results are in good agreement with the experimental results. When the excitation frequency is greater than 75%, the compaction effect is high. The results of this study can provide the basis for efficient compaction of asphalt mixture.