Computation of Vibration Response of Aircraft Due to the Gap Between the Track and Roller in the Flap Subjected to Unsteady Flow

This study explores the impact of flap gaps on aircraft cabin vibrations, focusing on the dynamic responses of flap structures under aerodynamic excitations. Flaps are crucial for aircraft control, especially during takeoff and landing. Common issues in flap systems, such as wear on slide tracks, bearing clearances, and bushing slippage, introduce gaps that amplify vibration amplitudes. A time–domain method, employing a spring–beam model, was used to convert aerodynamic loads into structural loads, providing detailed insights into flap dynamics and their influence on the aircraft. Computational fluid dynamics software was utilized to calculate aerodynamic force distributions, and the effects of varying gap sizes on constraint forces and vibration responses were analyzed. The results indicate that increasing gap width reduces the maximum constraint force at the flap, altering the vibration characteristics. The study also reveals that higher vibration responses occur in the fore section of the fuselage due to modal superposition of frequencies near those of the flap support forces. Enhancing the stiffness of gap elements can mitigate abnormal vibrations, thereby improving aircraft performance and passenger comfort. This paper offers a quantitative analysis of the effects of flap gaps, serving as a technical reference for diagnosing faults based on cabin vibrations. These findings are critical for advancing aircraft design and maintenance practices, contributing to improved safety and reliability under extreme flight conditions.