Developing a hybrid phenomenological model for predicting the sound absorption coefficient of a pineapple leaf fibre/waste tea leaf fibre/glass fibre/epoxy-based natural fibre-reinforced hybrid composites is the predominant topic of this article. Phenomenological models excel at extrapolating characteristic impedance and wave number whereas empirical models require fewer inputs but overlook wave propagation in pores. Existing models apply only to single-fibre-reinforced composites, necessitating the creation of a hybrid model for hybrid composites. The developed hybrid Zwikker–Kosten and Johnson–Champoux–Allard model shows good agreement with experimental data across the frequency range, with standard deviations of 0.001–0.029 and percent deviations of 1.11%–11.43%. The overall noise reduction coefficient between the model and experiments is 0.31 vs. 0.30, with a 3.33% deviation. Furthermore, the application of alkali treatment increased the surface roughness which in turn, enhanced the sound absorption capabilities of these composites. The increased fibre roughness also amplified friction between fibres and sound waves, resulting in higher sound absorption coefficients. In addition, X-ray diffraction, thermal stability (thermogravimetric analysis and differential scanning calorimetry), and scanning electron microscopy examinations were performed on the designated composition (5% by weight of pineapple leaf fibre and 25% by weight of waste tea leaf fibre) of the pineapple leaf fibre/waste tea leaf fibre/glass fibre/epoxy-based natural fibre-reinforced hybrid composite.

中文翻译：

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采用唯象模型预测茶树/菠萝/无碱玻璃纤维环氧混合复合材料的声学行为

本文的主要主题是开发一种混合唯象模型来预测菠萝叶纤维/废茶叶纤维/玻璃纤维/环氧树脂基天然纤维增强混合复合材料的吸声系数。唯象模型擅长推断特征阻抗和波数，而经验模型需要较少的输入，但忽略了孔隙中的波传播。现有模型仅适用于单纤维增强复合材料，因此需要为混合复合材料创建混合模型。开发的混合 Zwikker-Kosten 和 Johnson-Champoux-Allard 模型在整个频率范围内与实验数据表现出良好的一致性，标准差为 0.001-0.029，百分比偏差为 1.11%-11.43%。模型与实验的总体降噪系数为0.31 vs. 0.30，偏差为3.33%。此外，碱处理的应用增加了表面粗糙度，从而增强了这些复合材料的吸声能力。纤维粗糙度的增加还放大了纤维与声波之间的摩擦力，从而导致更高的吸声系数。此外，对指定成分（5%重量的菠萝叶纤维和25%重量的废茶叶纤维）进行了X射线衍射、热稳定性（热重分析和差示扫描量热法）和扫描电子显微镜检查。菠萝叶纤维/废茶叶纤维/玻璃纤维/环氧树脂基天然纤维增强杂化复合材料的制备。