基于微观结构的多孔沥青混合料吸声模型

为了在设计阶段实现基于设计参数的多孔沥青混合料吸声性能预估,构建了基于微观结构的多孔沥青混合料吸声模型.依据声-电类比理论,计算了多孔沥青混合料吸声模型的声阻抗和吸声系数;运用图像处理技术及统计分析方法,得到了多孔沥青混合料"特征孔隙直径";依据多孔沥青混合料吸声模型微单元体中毛细管长度随圆球与毛细管截面直径比值的变化规律,得到了微单元体中毛细管的结构参数取值.结果表明:所构建的多孔沥青混合料吸声模型预测的给定声波频率下试件最大吸声系数及其对应频率与驻波管法实测值之间具有良好的相关性,验证了该模型在预测多孔沥青混合料吸声特性方面的准确性.

Acoustic Absorption Model of Porous Asphalt Mixture Based on Its Micro Structure

In order to predict the acoustic absorption characteristics of porous asphalt mixture based on design parameters in design stage, a new acoustic absorption model of porous asphalt mixture was proposed based on its micro structure. The acoustic impedance and coefficient of acoustic absorption of porous asphalt mixture were calculated with the electro acoustic analogy theory. The diameter of characteristic air void of porous asphalt mixture was proposed by using image analysis techniques and statistical analysis theory. The capillary structure values of micro element were obtained by analyzing the relationship between length of capillary and sphere capillary diameter ratio of micro element. Results show that there is a good correlation between the predicted maximum coefficient of acoustic absorption and responding frequency, using this acoustic absorption model of porous asphalt mixture, and tested values with standing wave tube. Ultimately, this acoustic absorption model of porous asphalt mixture was verified as a powerful and robust tool in modeling and predicting the acoustic absorption characteristics of porous asphalt mixture.