The Influence Of State Equation And Constitutive Model In Numerical Simulation Of Hypervelocity Impact

Along with the quick development of astronautics,the environment of orbital debris was exacerbated,which greatly threatens orbiting spacecraft.It is needed urgently to design defence for the large spacecraft with longevity and great credibility aganist orbital debris impact. In order to enhance spacecraft's viability in this environment,the research on protection technology which insure aircraft operation reliably and safely has become the emergent mission already.There are three methods for researching Hypervelocity Impact,i.e. theoretical research, numerical simulation and experimental research. At present the velocity can only arrive to 7-8km/s in the experiment, and is limited by the by projectile size. Meanwhile,the observation and testing process involves photographing photography technology, the sensor technology and other disciplines, these techniques applied in processing super-fast collisions has immense limitations. In addition the costly research fund and the expensive maintenance costs are limited,Especially,during the Hypervelocity Impact experiment,the launch of the projectile damage seriously to the launch device.So these factors have limited the experimental progress. Along with the development of numerical calculation techniques,numerical simulation techniques can be used in many field.Along with theoretical foundation get more and more ferfect.numerical simulation can be used to research many prombles which can not be researched in the experiment and its research can not be limited by the conditions of super-fast collision Chooseing the equation of state and constitutive model has great influence in simulation results. In order to improve the accuracy of the results of numerical simulation, chooseing suitable state equation and constitutive model is extremely important.So in this paper we research the influence of state equation and constitutive model in numerical simulation of hypervelocity impact through the debris cloud and the numerical simulation of curve ballistic limit.The research in this thesis as follows:(1)First in numerical simulation,this thesis get more accurate results of numerical simulation in the velocity scope at 3-4 kilometers in terms of Gruneisen state equation and Johnson - Cook constitutive model,but the error will magnigy along with the Projectile diameter for this collocation.So this collocation suited to 3-4 kilometers. Liear state equation isn't suitable numerical simulation of velocity characteristic of the debris cloud ;The simulation results simulated respectively by Tilloston, Puff and Polynomial state equations accord with the results of the experiment directionally,but it is not identical with experimental value quantitatively.(2)Second in the simulation of speed point,the results of Steinberg constitutive model is better than Jonoson-Cook constitutive model .(3) Third Ballistic limit curve is one of the important problem,this thesis ues the different collocation which include different state equation and constitutive model.acquire the suitable collocation for the different speed point which by contrast the simulation result with the experiment data.