Research On Energy Absorbers Of Legged-type Lander And Dynamic Simulation On Its Soft Landing Process

With the rapid development of space technology, the human exploration of theuniverse continued to deepen, in the new round of international space exploration,the countries in the world to carry out the landing stars technology research. Thelander buffer device is the success key to planet soft landing, although the UnitedStates and the former Soviet Union has been successful landing on Moon and Mars,but our design research on buffer device used in planetary soft landing areas are stillin its infancy, there are a lot of key technologies need to overcome. This studysupported by the National Natural Science Foundation of China project the landersnew buffer structure intelligent design approach and landing stability analysis, tocarry out legged lander buffer device characteristics and key technologies for ourPlanetary Lander and provide the theoretical basis and technical support.This workhas important technological and political significance.Honeycomb structure as a legged lander buffer device core component, itsquasi-static compression mechanical behavior is the basis of analysis of thecushioning properties of honeycomb structure.This paper analyzes typicalhexagonal honeycomb, and takes Y-cellular cell mechanics model for hexagonalsymmetry structure.The hexagonal honeycomb mean stress theory model has beenbuilt by simplified ultra-folding unit theory based onTresca and Mises yieldcriterion. The peak stress model of hexagonal under quasi-static load is built basedon the theory of elasticity. Compression experiments for nine different aluminumhoneycomb specimens demonstrated that the correctness fordeveloped mean stressand peak stress theory model of hexagonal honeycomb structure.Giving goodfoundation for the follow-up study of honeycomb structure energy absorptioncharacteristics and energy absorption properties of energy absorber used in leggedlander under impact conditions.For buffer device is usually under the impact load, dynamic mean stresstheoretical model for hexagonal honeycomb under impact loading is developedbased on thin plate bending theory. On this basis, mathematical model of specificenergy absorption for hexagonal honeycomb structure is built and analyzed theinfluence of impact speed on the dynamic stress.Finite Element Analysis is used to analyze the influence of different cellularunit cell angle on dynamic energy absorption characteristics.Nine different specifications of the regular hexagon aluminum honeycombtests are did in impact testing machine to test the dynamic energy absorptioncharacteristics and verify the correctness of the theoretical model and the calculation accuracy of the finite element model.To expand the application the useof honeycomb structures in energy-absorbing field, analysis of the influence of gasin the honeycomb cells on dynamic mean stress.Finite element analysis models arebuiltfor different topological honeycombstructures under impact load, square honeycomb and other five parametric modelinganalysis programs are developed.Analysis of the honeycomb structure parametersand the relative density of the dynamic energy absorption characteristics.Themathematical modelsof peak stress, the specific energy absorption of mass andspecific energy absorption of volume are built by response surface method.Maximum energy absorption is set as the optimization goal, the design of optimalenergy absorption of honeycomb structure parameters is did for differenttopological honeycombs.The results not only provide technical support for theenergy absorption optimization of honeycombenergy absorber used in leggedlander.And it is very important to solve the buffer device lightweight andlow-volume design problems.For the lander buffer device miniaturization and lightweight design goals,considering the design efficiency and cost of the lander buffer device,this studyproposed legged lander buffer device design process and designrequirements.Taking four-leg cantilever lander as research object, optimize energyabsorption ability of series honeycomb cushioning device used in legged lander.Development legged lander cellular cushioning device optimized designprocess, to optimize the design of energy-absorbing characteristics based on thespecific energy absorption maximum cushioning device and get the bestcombination of honeycomb structure. Finite element model is built to analyze thetwo series the cellular cushioning device buffer performance, through experimentsverify the accuracy of the finite element model.Create virtual prototype model oflegged lander for soft landing, typical legged lander landing mode soft landingsimulation to verify the effect of cushioning device buffer, and provide a theoreticalbasis and technical guidance for buffer legged lander device design.