Design And Optimization Of A Certain Type Of Launch Vehicle Landing Mechanism Based On CAE

Lift is composed of landing gear,lifting components and power components,in transport and launch missiles are play an important role.Traditional lift adopts hydraulic vertical,but as it cannot meet the missile weapons in requirements such as high precision,high speed,automation,and gradually replaced by electric shaft.Compared with hydraulic vertical hoisting,electric vertical hoisting brings more load impact to the landing mechanism,which requires higher reliability and stability of landing gear.In addition,the traditional landing gear design based on engineering experience,the results are not reasonable,it is difficult to meet the performance requirements of electric vertical requirements.Therefore,it is of practical significance to study the landing mechanism,reduce the impact of load impact and optimize the landing gear structural performance.Taking the take-off and landing mechanism of a certain type of launch vehicle as the research object,this paper conducts dynamic simulation analysis on the vertical processes of four vertical modes in a certain vertical time,and determines the mode with the minimum impact load.Then the finite element numerical simulation is carried out for the landing gear in this mode to clarify its structural bearing characteristics and material distribution.Finally,based on this,the landing gear was optimized with multi-objective and multi-variable parameters,and the optimized structure was verified by numerical simulation.Firstly,the structure of the landing mechanism was analyzed,and its dynamics simulation model was built in ADAMS software.By analyzing four common vertical modes,the dynamic numerical simulation of the landing mechanism was carried out under different vertical modes.It is concluded that the vertical mode of"uniform acceleration-uniform velocity-uniform deceleration"has little influence on the stability of the landing mechanism,and the maximum value of the thrust required for vertical hoisting and the load at key hinge points under this mode is the minimum of the four modes,and the value of the vertical mode decreases 4.41?10~4N and4.42?10~4N.Secondly,the finite element analysis of landing gear is carried out to clarify its working performance and material distribution.Through analyzing the working condition of the gear for more statics,get the working condition of more than 90%of the area of stress concentration in 0 MPa–60 MPa,it is far less than the material allowable stress172.5 MPa,inadequate use of known structure of materials;Secondly,the prestress modal analysis is carried out on the structure.The first-order frequency of 2.43 Hz is close to the excitation frequency of 1 Hz,and there is resonance risk.At last,the transient dynamic analysis is carried out,and the impact of variable load has a great influence on the vertical riser.Finally,the landing gear is optimized and verified by numerical simulation.Through the topology optimization technique to determine the optimal landing gear power transmission path,and using the truss structure theory knowledge to build new conceptual model of landing gear.There are 16 important geometric dimensions in the parametric model,and the sensitivity analysis is carried out on them.Seven parameters,such as R2?R5?D1 and on,which have a great influence on the optimization target,are determined.Finite element numerical simulation on the optimized model,get the structure stiffness,strength,and prevent the respect such as resonance reliability has a certain degree of increase,but also reduces the quality of structure.The maximum equivalent stress was reduced by 44.55 MPa.The maximum displacement reduction is 13.06 mm;The first mode frequency increases by 6.97 Hz;Quality reduction of 9.18%.Finally,the submodel method is used to locally optimize the structure,and the maximum equivalent stress is reduced from 113.14 MPa to 100 MPa.