Dynamics simulation and bird-strike resistance design for civil aircraft landing gear

Bird strikes remain one of the major threats to flight safety, particularly during takeoff and landing phases. Despite this, the safety of landing operations following bird strike on the landing gear—an essential load-bearing system during these phases—has not received sufficient research attention. In this study, a finite element (FE) model of a strut-type nose landing gear system for a civil aircraft is developed to simulate both normal and repeated landing processes after a bird strike. The residual strength and fundamental performance of the landing gear structure post-impact are evaluated. Results show that, compared with an unimpacted landing gear system, bird strikes can significantly impair cushioning performance and reduce the safety margin. Under normal landing conditions, damping dissipation efficiency decreases by 9.75%, and the safety margin drops by 19.2% to 34%. For heavy landings, the damping efficiency is reduced by 2.8%, with a safety margin decline ranging from 14% to 38.8%. Based on the identified risks associated with bird strike, a design criterion for impact resistance and a corresponding reinforcement scheme are proposed. The effectiveness of reinforcement patches of varying thicknesses is further evaluated using the analytic hierarchy process (AHP), considering factors such as structural weight increase and safety margin improvement.