Analysis And Numerical Simulation Of Several Influencing Factors On The Stability Of Hypersonic Rocket Sled

The rocket sled is a high-precision ground simulation test equipment developed in the indoor and outdoor environment developed in the 1960 s.It is mainly used to build a high-speed test environment for the test specimens to facilitate the study of its dynamic performance in environments such as high-speed,high-acceleration and large overload operation,often used in aviation,aerospace,weaponry and other fields.The rocket sled runs on high-precision orbits with many uncertain nonlinear factors,such as engine thrust oscillations,high-temperature conditions,boots softening and wear,system quality continuity reduction,excessive speed shock reflection,Nonlinear aerodynamics.Meanwhile the strong coupling phenomenon between the shoe and the track due to aerodynamic lift,track irregularity,eccentric thrust,etc.,often accompanied by large energy loss.Based on the combination of theoretical analysis,numerical calculation and experimental verification,this paper systematically studies the dynamic response law of the rocket skid-track system coupling.The main research work is as follows:1.This paper completed the dynamic modeling of the hypersonic rocket skid-track coupling system.Firstly,the author established a relatively complete six-degree-of-freedom dynamics model of the rocket sled with multiple thrust skid system;then,Kinetic models were established rail Timoshenko beam model and finite element model based on discrete;lastly,the displacement and coordinating relations around shoe-orbit coupling is derived.The Flores contact force model is used to realize the mechanical model of the shoe-rail coupling.2.This paper established a rocket sled-orbit coupling finite element model of the system,and it can be verified by experiment.The article systematically studies the dynamicresponse characteristics of the rocket sled at 600m/s,and obtains the vibration of the skid body at each level: 1)The rocket sled system is a "pitching" movement,and the thrust skid is a kind of movement similar to "squatting water",accompanied by a certain "tail" phenomenon;2)The vibration response of the product skid is more severe than that of the thrust skid;3)The vibration response near the contact position of the two-stage skid body is more severe.3.This paper established the rocket sled-track coupling evaluation index and operational stability criterion.The paper uses the power spectral density method to analyze related dynamic response parameters,and its closeness to the inherent mode of the rocket sled is used as the basis for determining whether the rocket sled is stable.4.This paper completed the sensitivity study of the key influencing factors of the coupling of the boots and the track,and obtained the order of influence of each factor.The more significant factors affecting the dynamic response of the front slipper are: the running speed of the rocket sled,the stiffness of the shoes,and the stiffness of the track;However,as for the rear slipper,the more significant factors affecting the dynamic response are: the running speed of the rocket sled,the stiffness of the track,and the stiffness of the shoes;...