【摘要】 无纺织物反滤排水应用常处于不等轴双向受拉状态,拉应变引起无纺织物孔径变化,易导致反滤性能失效。基于现有两种体系的无纺织物孔径参数理论解,推导不等轴双向拉应变状态下无纺织物的等效孔径理论解O₉₅^bi、及孔径分布曲线变化理论解PSD_bi。采用前人等轴双向拉伸孔径试验数据,对比两种理论解对该试验的计算结果,并试算不等轴拉应变下两种理论解的预测结果。研究结果表明,PSD_bi理论解能预测等轴双向拉应变下孔径分布曲线的变化,不等轴双向拉应变下PSD_bi理论解的预测结果取决于方向参数K_a及应变值的大小。对等轴双向拉应变下O₉₅变化斜率的预测,O₉₅^bi理论解较准确,PSD_bi理论解计算结果偏大。O₉₅^bi理论解对于较厚无纺织物的O₉₅数值预测较为准确,对较薄织物预测结果偏小。以上误差与单向拉应变下两类体系公式的误差规律一致,该误差与模型的理论基础相关。更多还原

【Abstract】 Nonwoven geotextiles are typically subjected to unequal biaxial tension in filtration applications, which changes the pore sizes, and can easily cause the failure of material. This work investigates the analytical solutions for the equivalent pore size(O₉₅^bi) and pore size distributions(PSD_bi) subjected to unequal biaxial tensile strains. The experimental data collected from two nonwoven geotextiles under equal biaxial tensile strains are compared with the analytical solutions. The analytical variations of the pore size parameters under unequal biaxial tensile strain are calculated. It is concluded that the changes in analytical PSD_bi depends on the tensile strains and the directional parameter K_a. The experimental PSD curves under equal biaxial tensile strains correspond with the analytical predictions. For changes in O₉₅, the O₉₅^bi solution predicts more accurately than the PSD_bi solution. The O₉₅^bi solution predicts more accurately for the thicker nonwoven geotextiles. The same conclusion can be drawn from the results under uniaxial tensile strains in the literatures.更多还原