Nonlinear load-bearing characteristics of ski landing gear during drop impact on snow-covered pavement

Ski landing gears are core components that enable aircraft to take off and land safely on unpaved surfaces such as snow and swamps. They provide key technical support for operations in special environments, including polar scientific expeditions and air transportation in remote areas. However, most existing studies focus on paved surfaces, while analyses on the drop impact load-bearing characteristics of landing gears on snow-covered surfaces are relatively scarce. This scarcity makes it difficult to support the forward design of ski devices and the safety assessment of aircraft takeoff and landing in snowy environments. The drop impact load characteristics of ski landing gears on snow-covered surfaces are taken as the research object, and a dynamic analysis method for the snow load-bearing of landing gears is established by combining the Coupled Eulerian-Lagrangian (CEL) method and the Capped Drucker-Prager (CDP) snow constitutive model. The effectiveness of this analysis method is verified using test data from snow-covered flat plate settlement tests. On this basis, the impact load characteristics of three typical ski landing gears (fixed, strut, and articulated) during the drop impact phase are systematically studied, and the influence laws of sink rate and snow depth on vertical load-bearing are specifically analyzed. The simulation results show that a decrease in sink rate and an increase in snow depth significantly reduce the vertical peak load of the ski. When the snow depth increases from 300 to 500 mm, the peak load decreases by 52.4%. Meanwhile, compared with the energy absorption capacity of snow, the buffer plays a dominant role in energy dissipation. Compared with the articulated ski landing gear, an increase in sink rate directly affects the steady-state load distribution ratio between the wheels and ski of strut-type ski landing gear, significantly worsening the vertical load-bearing condition of the tires.