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  • A Method for Indentifying Thermal Characteristics of Aerospace Anisotrope Composite Materials

    Paper number

    IAC-05-C2.6.07

    Author

    Prof. Oleg Alifanov, Moscow Aviation Institute (MAI), Russia

    Year

    2005

    Abstract
    The reliability and accuracy of thermal modeling and design of spacecraft and launch vehicles depend to a large measure on adequacy of mathematical models employed from the standpoint  both of their structure selection and accuracy of models parameters. 
    Promising aerospace materials and structures call for nonlinear, multidimensional, unsteady and non-isotropic mathematical models to carry out the required thermal analysis. In particular, thermal state of many thermal protection and thermal insulation composite materials and structural members made of them can be described with a sufficient degree of adequacy by a two-dimensional, unsteady heat conduction equation in which the volumetric heat capacity depends on temperature and the residual thermal conductivity is a tensor the 
    elements of which are also functions of temperature. ln order to provide the desired exactness of calculations using this model, it is necessary to know the material' s thermal characteristics with a high degree of accuracy. More often than not the application of traditional thermophysical methods to determine these characteristics for modern anisotropic composite materials over a wide range of temperatures is associated with very large working time and, moreover, in so doing the results precision is far from perfect.
    In the paper a new method for complex identifying the thermal properties is considered as applied to critical aerospace materials which operate in conditions of extreme unsteady heat loading. The method is based on solving  a coefficient inverse problem for the above-mentioned nonlinear two-dimensional anisotropic heat conduction model.  The corresponding computational algorithm is constructed by the use of the iterative regularization method, B-spline approximation of unknown functions, the adjoint problem solution for defining the functional gradient and the 
    conjugate gradient method to realize  the the iterative process. Numerical experiments are given to illustrate the
    efficiency of the proposed method. This approach was used as the basis for computational-and experimental study
    of orthotropic composits on the testing facility TVS-1 in Moscow Aviation Institute.
    
    Abstract document

    IAC-05-C2.6.07.pdf

    Manuscript document

    IAC-05-C2.6.07.pdf (🔒 authorized access only).

    To get the manuscript, please contact IAF Secretariat.