Research On The Corrugated-core Sandwich Structure Scheme Of Hypersonic Vehicle

When a spacecraft flights at hypersonic speeds of over Mach 5 through planetary atmospheres,it will lead to extremely severe aerodynamic heating and pressures on the vehicle exteriors.To meet the demands of longer flight time(7200s)and higher Mach numbers,the corrugated-core sandwich structure as an Integral Thermal Protection System(ITPS)is designed for the hypersonic vehicle in which the load-bearing structure and the thermal protection structure are combined into on single structure.In this dissertation,the plane panels and cylindrical fuselage models of corrugated-core sandwich structure are established respectively.The heat transfer analysis thermo-mechanical analysis are carried out based on finite element analysis method.The goal is to demonstrate the feasibility of corrugated-core sandwich application in the hypersonic vehicle.The requirements of the ITPS are presented based on the severe aerodynamic heating environments and the demands of load-bearing capabilities.Then the thermal insulation performance,load-bearing capabilities,structural efficiency of corrugated-core sandwich and honeycomb-core sandwich panels are analyzed.Studies have show that the corrugated-core sandwich structure is more appropriate as an ITPS for hypersonic vehicle.Finally,the key technologies of corrugated-core sandwich ITPS are summarized.The heat transfer and thermo-mechanical coupling analysis models of plane corrugated-core ITPS panels are established.The temperature and stress distribution of different parts are obtained.The results indicates that the thermal insulation layer thickness has a significant effects of the bottom face sheet temperature,but only for short time heating load.Due to the contradiction between thermal and mechanical function,the structure exists heat short and thermal mismatch effects.Then several improved schemes are developed and have achieved good results.The heat transfer and thermo-mechanical coupling analysis models of cylindrical fuselage corrugated-core ITPS are established.By introducing the parameter,the heat transfer differences of plane panels and cylindrical fuselage are compared.The influence of temperature to the thermal load is considered,the heat flux is iteratively modified with heating time.Based on the thermal-mechanical coupling analysis,the temperature distribution,stress distribution,deflection,buckling eigen values are obtained,and then the impacts of holes in web and web numbers are studied.The paper systematically carried out in-depth corrugated-core sandwich structure research and discussed the application feasibility of hypersonic vehicle subjected to severe aerodynamic heating in long time.The results of this dissertation have certain value of engineering application in the ITPS design of hypersonic vehicle.