Design For Thermal Structure Of Flight Vehicle And Thermal-stress Analysis

At present, all the countries are trying to research aerospace flight vehicle ofthe new generation, making it gradually developed in the direction of faster andlighter. As the vehicle is faced with a complex and severe loading environmentthrough its access to the space, the thermal structure of the vehicle is the key factordeciding whether the vehicle can complete the mission successfully. To the design ofthe vehicle thermal structure, at first we should get the thermal and structure load ofthe vehicle through its working progress correctly. Different parameters are selectedfor each independent variable. The temperature and stress field is obtained throughthe analysis. The design of the structure is conducted based on the calculated result.In this paper, the thermal structure is designed. The thermal-stress coupling responseis also calculated taking the thermal structure of the vehicle as the research object.At first, the initial parameter and the material scheme are proposed based onthe dimensional requirement of the vehicle thermal structure. Then for the differentvalues of the independent variables, the static analysis finite element model of thethermal structure is established. The stress field and the stability are also analyzed.The strength and the stability are checked based on the appropriate strength theoryand the critical buckling coefficient. The parameter that meet the strength and thestability condition and minimize the quality of the structure is determined.The structure finite element model of heat transfer analysis is establishedtaking the unit cell model of honeycomb structure as the research object. A transientthermal analysis is carried out and the temperature field of the structure through itsflying progress is carried out considering the convection and radiation boundarycondition. The influence of different coating thickness, coating emissivity and loadsto the inside and outside temperature field of the structure is conducted. Theminimum coating thickness which makes the inner face temperature under themaximum working temperature of the structure is determined.The thermal-stress coupling analysis finite element of the whole vehiclethermal structure is established. The temperature field distribution of different partsin the whole progress is obtained. The result is compared with that of the unit cellmodel. The accuracy of the thermal-stress coupling analysis model is proved. Thestress field of the structure with thermal stress is calculated using a sequencecoupling method. An appropriate strength criterion is selected to make thethermal-stress coupling response of the structure less than the allowable stress of thematerial.