The FEA Research On Aseismic Peformance Of Recovery Airbag On UAV

The recovery of parachuting plus airbag is a recovery method of unmanned aerial vehicle with a higher safety. In order to choose a suitable airbag with reduced test times and development costs, preliminary results could be analyzed through computer simulation and then practical tests could be made to verify the computer simulating results. In view of this, this paper based on the finite element model, researches into the following two aspects:Firstly, various parameters of the airbag are inspected: height of the airbag, the initial pressure, relieving pressure (Characteristic Pressure),and some other parameters such as area of air outlet which influence the aseismic performance of airbags. By using the fluid cavity model provided by the finite element analysis software, this paper defines the airbag border with M3D4R element (one kind of Membrane elements) and defines gases' parameters and conditions such as the gas bulk modulus, thermal expansion coefficient of gas, gas heat capacity, the gas constant, the initial pressure, initial temperature on the reference point.Accordingly, adopting various models established in the computers, results in various circumstances have been analyzed, some conclusions are drawn: relieving pressure decides the position of fold points in the pressure curve, changes the value of relieving pressure, changes the shape of pressure curve to improve the efficiency of air bags; the area of air outlet mainly affects the trend of the maximum pressure and the pressure curve. The aseismic performance of airbags is related to the process, different recovery objectives and different airbag shape impact compression process of airbags, each available parameters combination are aiming at specific recycling goals and specific shape of the airbags. Secondly, the paper researches the overall unmanned aerial vehicle model in simplified conditions, the stress of the fuselage after the shock absorption landing, unmanned aircraft and overload airborne equipment, as well as the comparisons of the airbag compression situation front and back. Finally, the paper also compares with the results under two different conditions: with the impaction of the plane velocity and without.