Dynamic analysis and Pareto-based damping optimization of an aircraft gun buffer system with direction-dependent piecewise damping

Modern aircraft guns are subject to excessive recoil shock on the airframe and limited firing-rate performance during continuous shooting. To address these shortcomings, this paper proposes an asymmetric piecewise damping design for the aircraft gun buffer system, aiming to reduce the recoil shock and improve the firing-rate potential. The recoil and counter-recoil stages are represented by two independent direction-dependent damping coefficients, allowing the energy dissipation in the two motion phases to be regulated separately. An equivalent single-degree-of-freedom dynamic model is established, and the displacement response is derived using the equivalent linearization method and the harmonic balance method. The analytical solution is verified by the fourth-order Runge-Kutta numerical simulation. Parametric analysis shows that the influence of the damping coefficients on the recoil force is frequency-dependent. Increasing the recoil damping coefficient significantly suppresses the resonance-dominated recoil-force peak, while increasing the counter-recoil damping coefficient further reduces the recoil response near the design frequency but slightly increases the counter-recoil time. Therefore, the damping effect should be evaluated from a multi-objective perspective, and this paper introduces a Pareto-based damping selection procedure combined with an ε -constraint criterion to determine the optimal damping combination. The optimized results have been located, and it is found that the recoil force is reduced by approximately 14.1%, while the counter-recoil time increases by only approximately 0.46%, compared with the firing-rate-priority solution. This study can provide a theoretical reference for achieving the design objectives of a high firing rate and reduced shock on the airframe for aircraft guns based on the direction-related damping design.