Dynamic Simulation Of Combined Airbag Cushion And Collaborative Optimization Of Multiple Working Conditions

As a buffer device,the airbag can effectively absorb the impact energy brought by various collisions and is widely used in aerospace,military and even our daily life.It has the characteristics of high energy absorption efficiency,easy folding,simple operation and high adaptability.The research content of this paper is the application of the combined buffer airbag in the landing process of the re-entry capsule.According to the different landing sites,the reliability of the buffer system in the complex environment is improved by optimizing the design.In order to achieve the above design objectives,we conducted the following studies :Firstly,a single airbag model was established by using the control volume method.The buffer energy absorption of the airbag was studied by referring to the literature in this paper.The simulation data and experimental data were compared to verify the effectiveness of the modeling method and numerical calculation.Based on the above methods,the dynamics simulation model of the cyl indrical airbag was established,and its performance was found to meet the landing requirements of the reentry capsule.Secondly,the design parameters that can affect the cushioning performance of the airbag are studied.By using the control variable meth od,the influence rules of the initial air pressure,exhaust air pressure and exhaust area on the performance of the cushioning system are obtained.In order to study the impact of complex environment on the buffer system,the landing conditions at differe nt slopes and different ground were analyzed.The variation rules of airbag characteristics,reentry capsule motion characteristics and energy conversion of the buffer system at different landing sites are obtained.In the end,the air bag system is optimized by considering various recovery conditions.Based on the previous study,the dip angle and geological conditions of the landing ground were considered,in which the ground was hard sandy land and low-density dry sand,and the dip angle was 0°,5° and 10°.There were six landing conditions in the combination of the two factors.The main factors affecting the cushioning performance of the airbag were taken as the optimization design parameters,and the energy absorption per unit mass of the airbag and the peak overload of the re-entry capsule were taken as the optimization objectives.By using the optimal Latin hypercube test design method,the space of design parameters is sampled efficiently.The agent model is constructed by using kriging agent model and its veracity is validated effectively.Based on the constructed approximate agent model,NSGA-Ⅱ was used to optimize the airbag system.The results are verified by dynamic simulation.According to six working conditions,the cushioning performance,stabili ty and adaptability of the airbag system are strengthened.