摘要
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 compaction efficiency of asphalt paver and obtain high compacting effect,a forced vibration damped system composed of paving material and vibration screed equipped in asphalt paver was analyzed.The relationships among resonance region,the frequency ratio and damping ratio were obtained by investigating the interaction mechanism and dynamics between screed and paving material.Based on the resonance theory,a simulation model of＂mechanical-material＂system reflecting the relationships among paving material compactness,vibration parameters,system parameters were established to obtain variation curve of paving compactness-screed frequency.According to the analyses of the models for different paving materials,the best vibration frequency and effective frequency range were determined,and the simulation calculations and full-scale experiments about two typical mixtures including SMA-13 and AC-20 were used to verify the frequency characteristics of the paving compactness.Theresults show that for gap-graded mixture SMA-13,passing rate of 4.75 mm sieve is 24.3%,asphalt content（mass fraction,same in the following content）is 6.37%,and the best vibration frequency is about 30 Hz.For continuous gradation mixture AC-20,passing rate of 4.75 mm sieve is 40.3%,asphalt content is 4.31%,and the best vibration frequency is about 35 Hz.With the increase of asphalt content and proportion of coarse aggregate in mixtures,the best vibration frequencies reduce.The simulation calculation results and experiment results have the basically same change rule.When the excitation frequency is greater than 75% of the best vibration frequency,screed shows efficient compacting effect for the mixtures.The research results can provide the basis for efficient compaction for asphalt mixtures.
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2016年第7期152-158,共7页
China Journal of Highway and Transport
基金
陕西省交通运输厅科技项目(13-03k)
中央高校基本科研业务费专项资金项目(2014G3252006)
关键词
机械工程
熨平板
仿真模型
最佳振动频率
密实度
mechanical engineering
screed
simulation model
best vibration frequency
compactness
