Cushion Performance Analysis And Optimization Design Of The New Snap-method Airbag

For the obvious advantages of airbag such as simple structure, foldability, lowcost, production and processing convenience, it is widely used in occupant safety ofvehicle, cargo dropping, recycle of unmanned aerial vehicle (UAV), deep spaceexploration and other fields. At present, the combination of parachute and airbag is amethod of UAV’s recovery which has a higher safety factor. This thesis makes aresearch on the finite element method of airbag modeling by using the combinedmethod of numerical calculation and experimental verification. Based on the aboveresults, the simulation and optimization work of the airbag suspension recoverysystem for UAV is done. The main research results are as follows:(1) Based on the volume control algorithm and finite element theory, the finiteelement model of falling ball impacting airbag is established by LS-DYNA. Bycarrying out the airbag experiment, it is validated that our method of airbag modelingbased on LS-DYNA can effectively simulate the conditions of airbag impact. The dropweight centroid acceleration-time curve derived from simulation analysis is in goodagreement with the curve derived from the impact experiment.(2) Based on the technical requirements of the airbag in the recovery process ofUAV, the three-point airbag layout scheme for the double-wing UAV is proposed andthe initial parameters of airbag is obtained by analytical method. According to theseparameters, the recovery process of UAV using airbag as damping device is explored.By discussing the influence of vent orifice area, initial pressure and pop pressure, thedesign parameters meeting the cushion performance is obtained.(3) This paper put forward a new structure of snap-method airbag, by discussingthe finite element model of breaking rope, the finite element model of UAVsnap-method airbag suspension recovery is established. The influence of breakingforce, vent orifice area and pop pressure on the airbag cushion performance ofbreaking length L=100mm and L=200mm are discussed respectively. And the airbagcushion performance influenced by different airbag arrangement on the airbag withbreaking length L=200mm is also studied. By comparing the results of snap-methodairbag and traditional airbag in optimum conditions, it is found that the snap-methodairbag has a better performance.(4) Based on the polynomial surrogate model and multi-objective particle swarm algorithm, the multi-objective optimization of traditional airbag and snap-methodairbag’s cushion performance on UAV recovery process is carried out. Optimizationresults show that, the cushion performance of the optimized airbag is improved andthe cushion performance of the snap-method airbag is better.(5) Based on the6σ quality management method and Monte Carlo stochasticsimulation technology, the robust optimization design for of the snap-method airbagis conducted. The optimization result decreases the response wave of the objectivefunction vr, and the reliability of the constraint’s biggest overload apis improved.