The Dynamics Analysis Based On Simpack Of Rocket Sled

Take rocket sled large surface dynamic test system to simulate the dynamic characteristics of load in the process of flight,to reduce costs and test with difficulty.It has a good development prospects in the field of aerospace.The running stability of the rocket sled mainly affected by the slide rail irregularity and the running speed of rocket sled.So it is necessary for the rocket sled dynamic simulation analysis,to provides reference foundation for the design of the rocket sled.First,analyzed the force condition of rocket sled system and degrees of freedom of each element,and taken the beam to substructure analysis and modal analysis.Then,based on the theory of multi-body dynamics,simplified the rocket sled system model,used Simpack to establish the rocket sled system dynamics model with rigid beam and elastic beam.Analyzed parameters of rail irregularity.Taken Level 6 PSD of rail in United States as an example,to established rail irregularity that fit for the rocket sled system.Finally,different working conditions was carried out for the rocket sled system dynamics simulation.The simulation results are as follows:(1)Under the condition of other unchanged,the vertical and horizontal vibration acceleration amplitude of rocket sled increases with increasing speed,and presents the parabolic type growth.Under the condition of low-middle speed,the dynamic response of rocket sled on horizontal is stronger than the dynamic response on vertical.(2)Under the same conditions,the vibration acceleration amplitude of rocket sled with elastic beam is smaller than the rocket sled with rigid beam.Under the condition of low speed,the rate of rocket sled amplitude decreased is the fastest,the greater the speed,the rate of rocket sled amplitude decreased is slower.(3)The greater the speed of the rocket sled,the greater the stability index,the system is more volatile,after using elastic beam,the stability index decline.(4)The greater the speed of the rocket sled,the greater the shape variables of elastic beam,and under the condition of low-middle speed,the lateral deformation of elastic beam is bigger than vertical deformation.