Dynamics Analysis Of A Rigid-flexible Coupling System Composed Of A Spacecraft With An Axially Moving Flexible Beam

More brilliant development of aerospace science and technology in the 20 th century,entering the 21 st century,the structure itself and operation environment of spacecraft are considered more complex and delicate with the rapid development of space technology and space technology.In order to more accurate research on movement characteristics of the spacecraft in the space environment,the space engineering puts forward higher requirements on structural dynamics.The flexible appendages of spacecraft are inevitably influenced by solar radiation,the spacecraft attitude control,the space debris and other disturbances.And dynamic response induced by these disturbances is difficult to decrease.In order to deal with the spacecraft development toward the direction of large-scale,complicated and precise manufacturing and improve the service life of the spacecraft,operation precision and work efficiency,considering the rigid-flexible coupling effect between the flexible axially moving beam and the spacecraft body is very necessary.Firstly,the traditional model of axially moving cantilever beam without considering rigid-flexible coupling effect is researched.The approximate solutions of the cantilever beam are solved by adopting the multi-scale method and the assumed mode method.In order to verify the correctness of the algorithm,the solutions of two methods are compared with previous results.Then,the floating coordinate formulation is employed to establish the rigid-flexible coupling system dynamic model for the axially moving flexible beam and the spacecraft body.Considering coupling effect between the axially moving flexible beam and the spacecraft body,the dynamic equations of the rigid-flexible coupling system are derived by using the Hamilton's principle,and the solutions of the dynamic equations are solved by adopting the separation variable method and the assumed mode method.Finally,several numerical examples are analyzed by using the fourth order Runge-Kutta method in numerical calculation.The effect of the radius and surface density of the spacecraft body and the axial velocity of the flexible beam on the transverse vibration of axially moving flexible beam and the attitude angle of the spacecraft body are researched by above several numerical examples.The study shows that the effect of the radius of spacecraft body in the different radius values range on the transverse vibration of flexible axially moving beam and the attitude angle of spacecraft body is different.When the radius of spacecraft body is less than the upper limit value of the radius in irregular range,the amplitude of tip displacement of flexible beam and attitude angle of spacecraft body is increasing and decreasing over time;When the radius of spacecraft body is in regular range,the amplitude of tip displacement of flexible beam and attitude angle of spacecraft body is increasing if deploying and the amplitude of tip displacement of flexible beam and attitude angle of spacecraft body is decreasing if retracting over time;When the radius of spacecraft body is greater than lower limit value of radius in no influence range,considering the rigid-flexible coupling effect between the axially moving flexible beam and the spacecraft body is completely unnecessary.