The present study aims to explore free vibration analysis of hybrid reinforced porous composite plates subjected to fluid loading. The hybrid composite comprises a porous core layer covered by two reinforced porous face sheets. Graphene Platelets (GPLs) and Carbon Nanotubes (CNTs) are considered as reinforcement materials. The linear three-dimensional piezo-elasticity theory is employed to model the structural part of the system, while the classical Rayleigh integral is used to obtain the fluid interaction part. The accuracy and reliability of the proposed model are validated by comparing the calculated natural frequencies of the plate in vacuum and water-loaded conditions with those reported in the literature. For the first time, several parametric studies are performed to investigate the effects of dimension ratios, porosity distributions, reinforcement dispersion pattern, porosity coefficient, and weight fraction of nanofiller on the natural frequency of hybrid reinforced porous composites. The results indicate that adjusting the porosity and weight fraction of the face sheets can enhance stiffness without changing the mass, emphasizing the importance of hybrid composites for achieving optimal stiffness while maintaining a constant mass. Furthermore, the influence of core layer porosity distributions on the composite behavior differs from that of porosity distributions in the face layers. Additionally, the effectiveness of the reinforcement pattern depends on the type of porosity distribution in the face layers.

中文翻译：

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流体加载下杂化 CNT/GPL 增强多孔复合材料板的自由振动分析

本研究旨在探索混合增​​强多孔复合材料板在流体载荷作用下的自由振动分析。该混合复合材料包括由两个增强多孔面板覆盖的多孔芯层。石墨烯片（GPL）和碳纳米管（CNT）被认为是增强材料。采用线性三维压电弹性理论对系统的结构部分进行建模，并采用经典的瑞利积分来获得流体相互作用部分。通过将计算出的板在真空和含水条件下的固有频率与文献中报告的固有频率进行比较，验证了所提出模型的准确性和可靠性。首次进行了多项参数研究来研究尺寸比、孔隙率分布、增强材料分散模式、孔隙率系数和纳米填料的重量分数对混合增强多孔复合材料的固有频率的影响。结果表明，调整面板的孔隙率和重量分数可以在不改变质量的情况下提高刚度，这强调了混合复合材料在保持恒定质量的同时实现最佳刚度的重要性。此外，芯层孔隙率分布对复合材料行为的影响与面层孔隙率分布的影响不同。此外，增强图案的有效性取决于面层中孔隙率分布的类型。