Finite Element Simulation of Contact Mechanics and Tribological Behavior in Gas-Filled Shock Absorbers for Light Delta Aircraft

Shock absorbers in aircraft landing systems undergo severe dynamic loading and repeated sliding contacts, making tribological performance a critical factor for reliability and service life. This study employs the Finite Element Method (FEM) in ANSYS to investigate the contact mechanics and stress distribution of a gas-filled shock absorber used in light delta aircraft under various landing overload conditions (2×, 4×, and 8× gravitational loads).A detailed three-dimensional model was developed, incorporating realistic geometry of the cylinder, piston, piston rod, and gas chamber. Special attention was given to contact interactions between the piston and cylinder wall, rod and end cap, and sealing interfaces. Frictional contact formulation was applied to simulate sliding motion under impact loading. Material properties, nonlinear contact behavior, and boundary conditions were carefully defined to replicate actual operating conditions.Simulation results reveal von Mises stress distribution and contact pressure patterns in critical tribological zones. At 2× overload, stresses remain within safe limits with moderate contact pressure. As overload increases to 4× and especially 8×, significant stress concentrations appear at sliding interfaces, indicating potential risks of wear, surface fatigue, and material degradation. The analysis highlights how contact mechanics and friction influence the overall structural response and energy dissipation performance of the shock absorber.The findings provide valuable insights for optimizing material selection, surface treatments, and lubricant choices to enhance tribological performance, reduce wear, and improve durability under repeated landing impacts. This research demonstrates the effectiveness of advanced FEM simulation in evaluating tribological contacts within high-performance mechanical components, contributing to the development of more reliable and longer-lasting shock absorption systems in aerospace applications.