Modal and random vibration analysis for structural design of aircraft external stores

This study introduces a novel methodology for the structural design of aircraft external stores, focusing on the integration of modal and random vibration analysis through the Power Spectral Density (PSD) method. The primary goal is to develop a robust design approach that enhances structural reliability and avoids resonance, a critical challenge in aerospace applications. Unlike conventional methods, this research presents a convergent strategy combining Finite Element Analysis (FEA), Computational Fluid Dynamics (CFD), and fluid-structure interaction to accurately predict stress, displacement, and frequency responses under dynamic loading. The methodology is specifically applied to external stores mounted at the fuselage station of a subsonic turboprop aircraft. A key novelty of the work is the validation of structural response through PSD-based vibration analysis, offering a high-fidelity prediction of dynamic behavior. Results indicate a close correlation between FEA and vibration outcomes, with maximum stress and deformation well within material limits and outside the aircraft’s natural frequency range, thus avoiding resonance effects. The conclusions of this study provide a roadmap for the design of aircraft stores based on modal and random vibration analysis. The proposed methodology helps to understand aeroelastic behavior, avoid resonance, resist aerodynamic forces, and prevent structural damage to aircraft external stores.