Optimization Method Research for Stiffened Thin Wall Structure’s Vibration Suppression Based on Parametric Modeling Technique

Abstract

Stiffened Thin Wall Panel Structure is a widely used structural configuration in the design of aircraft’s inlet duct and large open bay. Vibration fatigue failure of stiffened panel structure will quickly emerges under strong broadband random loading environment which caused by shock waves moving at the inlet lip and cavity vortex and shear layer oscillation during flight. At present, a main research focus on dynamic strength design of aircraft’s light-weight structure is to reduce the dynamic stress response level in broadband random vibration environment ,so as to improve the ability of thin wall panel’s vibration fatigue property with light structure weight. Taking a stiffened thin panel of inlet duct as a typical case under random vibration excitation environment, an Advanced dynamical topology optimization methods is established based on the parametric modeling technique . Within the main frequency domain of external dynamic load, the maximum root mean square of stress (MRMSS) for global element of stiffened panel structure is calculated and optimized under the weight constraint with Genetic Optimization Algorithm (GOA). The comparison of structural stress response before and after optimization design shows that the maximum element RMS dynamic stress is reduced by 38% with the weight increased by about 9.8% and the purpose of improving vibration fatigue property is reached.