Design And Analysis Of Landing Absorber System For Vertical Takeoff And Landing Launch Vehicle

The study of reusable vertical takeoff and vertical landing(VTVL)launch vehicle technology has become a major trend.The landing buffer system is one of the key components of VTVL reusable launch vehicle.It is of great significance to design,optimize and test the landing buffer system.In this paper,the buffer system of VTVL reusable launch vehicle is taken as the research object.The design and optimization of its overall layout and buffer device are carried out.And landing test is conducted.The main contents are as follows:Based on the overall parameters and technical index of a certain launch vehicle,the landing buffer system is designed.The two-dimensional retractable geometric model of the landing support is abstracted and the landing dynamics model is established.The collaborative optimization method is used to optimize the multi-objective performance of the buffer system.The optimization results show that the performance of the optimized landing buffer system is significantly improved.Aiming at the randomness of the landing conditions of the launch vehicle,a magnetorheological shock absorber applied to the VTVL launch vehicle is designed.A co-simulation model is established.The fuzzy control algorithm is used to semi-active the magnetorheological buffer.The simulation results show that the magnetorheological buffer is more efficient and can reduce the launch vehicle’s overload under the four-leg landing condition compared with the oleo-pneumatic shock absorber.Based on the prototype of the landing system,the landing impact test is carried out.The test results are consistent with the simulation analysis results,which verifies the accuracy and reliability of the simulation model.A new two-stage crashworthy damper which contains the oleo-pneumatic shock absorber and the honeycomb damper is proposed.The soft-landing dynamic model is established.The collaborative optimization is adopted to optimize the design parameters of the two-stage crashworthy damper.The results show that the maximum acceleration and the landing pillar force of the launch vehicle decrease after the optimization.Comparing with the oleo-pneumatic shock absorber,the two-stage crashworthy damper has advantage in reducing the launch vehicle’s maximum impact acceleration and the buffer pillar’s maximum force.