A complete approach for evaluating the vibrational behavior of RTM-manufactured functional composites under random vibrations

This paper introduces an innovative methodology for evaluating the vibrational behavior of functional composites reinforced with nanoparticles under random vibration loads. The novelty of this work lies in providing a comprehensive PSD-based frequency-domain approach, rather than conventional temporal methods, to characterize the dynamic response of such composites. The proposed model integrates: 1) a numerical simulation of nanoparticle-filled resin injection in a fibrous preform, validated against experimental data; 2) a homogenization model to determine the composite's mechanical properties based on constituent volume fractions; and 3) a finite element model coupled with PSD analysis to assess the vibrational response. The addition of nanoparticles enhances out-of-plane mechanical properties (E₂₂, G₁₂, G₂₃) while increasing weight and having minimal impact on E₁₁. Modal analysis reveals lower natural frequencies in bending modes but higher in torsional modes. Spectral analysis shows that acceleration and stress PSD peaks occur at modes 1 and 3 with functional composites exhibiting higher PSD values. A parametric study varying particles (0 %, 20 %, 40 %) and fiber volume fractions (45 %, 50 %, 55 %) indicates that increasing nanoparticles degrades vibrational performance, while a higher fiber fraction improves response with negligible impact on failure risk. This study provides a modern and effective framework for optimizing functional composites subjected to stochastic vibrations, addressing the lack of PSD-based frequency-domain analyses for nanoparticle-reinforced composites, which have previously only been studied in temporal methods.