Research On Mars Flexible Airbag Landing Cushion Characteristics Based On Discrete Element Method

As the mission of Mars exploration in various countries gradually shifts from surround detection to landing patrol detection,the airbag cushion system has become a new research hotspot.Because of its short research cycle,low research costs,and comprehensive data records,numerical calculation methods have become the first choice for researchers to optimize the design of airbag systems.Different from the previous research,using finite element method to optimize the airbag parameters,this topic proposes a discrete method to establish the airbag landing cushioning characteristics simulation platform based on the discrete surface topography of Mars,and realizes the airbag landing environment.The high-precision reduction facilitates in-depth study of the impact of the landing environment on the landing characteristics of the airbag system,and predicts the characteristics of the airbag cushion landing for the Mars environment,providing reference for the optimal design of the Mars buffer airbag and the selection of landing points.The airbag is the object of the simulation study of the landing cushioning characteristics.Therefore,the modeling method of the airbag discrete element model has become the primary problem in the simulation platform for landing cushioning characteristics.In order to establish the discrete element model for airbags,the dissertation combines the discrete element theory to transform the airbag microelements into a three-dimensional particle-spring model.Then the parameters of the particle-spring model are matched using simulation and theory,and the single-balloon airbag is used to make use of discreteness.Meta software EDEM completes the optimization of airbag modeling methods.On the basis of the single-ball balloon discrete element model,the feasibility of the discrete element model was verified,the specificity of the airbag cushioning characteristics on the discrete impact surface was verified,and the main parameters affecting the airbag cushioning characteristics were obtained.Firstly,through theoretical derivation and simulation analysis of the buffering process,the functional relationship between acceleration acceleration and each parameter is obtained;then the feasibility of the model is verified through simulation,experiment,and theory comparison;finally,the continuous surface is compared with the discrete surface.Simulations verify the specificity of the cushioning properties of the airbag on a discrete impact surface,and for the dynamic behavior of the particles in a discrete surface,a three-state transformation of the particles under the impact surface is proposed.Based on the single-ball model study,the multi-balloon airbag cushioning properties under Mars environment are predicted.Firstly,a discrete impact surface with a fire star shape and a discrete element model of a multi-balloon airbag were established.Then,a series of sample points were selected for simulation calculation based on the main parameters affecting the cushioning properties of the airbag.After the simulation was completed,multiple data points were used for the sample data.Non-linear regression analysis obtains the relationship between each parameter and the airbag system overload acceleration,and then completes the prediction of the airbag cushioning characteristics in the Mars environment.Through the research of this paper,we have obtained a simulation platform that can highly restore the Mars environment and predict the airbag cushioning properties.The cushioning performance of different parameters of the airbag system in the Mars environment can be obtained by using this platform.At the same time,simulation models of different impact surface parameters can be established to study the impact of different types of landing sites on the buffer characteristics,which is a simulation of the later Mars airbag soft landing technology.Research provides new ideas.