Dynamic Analysis And Active Vibration Control Of Missile Structure Based On Travelling Wave Method

Missile will undergo complex and harsh acoustics-vibration environment at thestage of missile launch and flight. Such dynamic environment would seriouslyendanger the safety and reliability of the missile structures and equipments ofmissile, so it is imperative to study effective dynamic analyses and vibration controlmethods. Traditional Finite Element Method and Statistical Energy Analysis areinadequate for dynamic analyses and control problems of missile structures in themid-high frequency range. On the basis of previous researches at home and abroad,missile simplified non-uniform beam structure is studied in the paper. The dynamicmodel is established by Travelling Wave Method, and the accurate dynamicresponse characteristics are obtained. Then the corresponding active vibrationcontrol method is explored to improve the reliability and accuracy of the missilestructure. In this paper, the specific research works are as follows:First of all, the most used cantilever beam structure in engineering is taken asan example. The dynamic model of cantilever beam structure is established byTravelling Wave Method, and accurate analytical solution is given. On this basis,active power flow expressions of the cantilever beam structure are derived in orderto study active control method of power flow for cantilever beam structure.Numerical simulation analyses are made for specific examples, and the results showcharacteristics and advantages of Travelling Wave Method and active controlmethod of power flow to deal with structural dynamic response analyses and activevibration control problems.Secondly, the vibrations of missile simplified non-uniform beam structure areconsidered as the superpositions of different forms and frequencies of elastic waves.Considering boundary conditions of force equilibrium and displace continuity,boundary conditions at the edge and mutual coupling join conditions between twobeams, the travelling wave dynamic model of the missile structure is establishedwhich contains longitudinal and flexural waves. Based on the model, the numericalsimulations of dynamic characteristics for missile structure are made by TravellingWave Method, and the results in comparison with the results by Finite ElementMethod show the correctness, accuracy and computational efficiency of TravellingWave Method for the problems of the dynamic response of the missile structure.Finally, on this basis of travelling wave dynamic model and the obtaineddynamic analyses, active control method of power flow for suppressing thevibrations is studied for missile structure. The expressions of active power flow offlexural and longitudinal waves for missile structure are derived. On this basis, active control of power flow is studied to suppress effectively the vibrations of themissile structure. The research results show that the active control method of powerflow can effectively suppress the vibration level of overall missile structure. Thesmall error of optimal control forces, the location of optimal control forces anderror sensors have little effect on the active control effect of power flow.Based on Travelling Wave Method and the theory of active control of powerflow, the dynamic analyses and active vibration control problems of missilesimplified non-uniform beam structure are studied in detail in the paper. Theresearch results will provide a valuable reference for the overall design, vibrationanalysis and active control of new missile in the future.