159 research outputs found

    Multiple inverse problem

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    The problem of providing the required level of quality of products and/or technological processes often becomes difficult due to the fact that there is no general theory for determining optimal sets of values of primary factors, i.e. output parameters of parts and units comprising an object as well as ensuring the equivalence of object parameters to the quality requirements. This is the main reason why the development of complex systems and objects of vital importance takes several years. To create this theory, one has to overcome a number of difficulties and solve the following tasks: creation of reliable and stable mathematical models that indicate the influence of primary factors on output parameters; determination of accurate solutions when mathematical models are poorly stipulated; and creation of a method of assigning nominal values and tolerances for primary factors with regard to economical, technological and other criteria. All of the above-listed tasks are equally important. The present work is an attempt to describe a solution for this problem. The mathematically formalized aspect of the problem of providing the required level of quality has been called the “multiple inverse problem”

    Identification of Physical and Mechanical Properties of Compound by Solving Inverse Problems

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    The paper presents a method of identification of physical and mechanical characteristics of the compound (calculated and experimental test method parameters). The idea of the method is that the studied material is connected with other materials, the characteristics of which are well known and differ from the characteristics of the material. Desired physical and mechanical properties should be considered unknown in the proposed calculation model, and the values of the parameters of trial constructions that can be measured accurately with experimental methods in the process of product operation, as well as characteristics of test materials and geometric dimensions of proposed structures are suggested to be placed in the same model as input information

    Acoustic emission and methods of its registration (review)

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    Lately a tendency is observed for the steady growth of requirements applied both to construction materials as well as to the methods of estimation of their reliability and quality. Particular attention is paid to the development of new, physically reasonable criteria of structural durability of materials, based on comprehensive study of the phenomena, which form the basis of processes of deformation and fracture. Such approach is supposed to enhance our understanding of the nature of durability and mechanisms of fracture of materials on different scale levels. This is possible only when analysis of these phenomena is accomplished by means of modern physical research methods as well as applying acoustic emission techniques for diagnostics of the fractures

    Calculation of mechanical stresses in adjoint system of electronic component and compound and strength assessment

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    The paper represents mathematical model and formulas developed for project calculations which are applied to sealed electronic units and provide assessing strength of passive electronic components having revolution shape (capacitors, resistors, diodes, pins, etc.). The stress calculation has been produced for materials of resistor and compound in the temperature interval (from –60 to +70°C) along the radius of resistor and compound

    Multiple inverse problem

    Get PDF
    The problem of providing the required level of quality of products and/or technological processes often becomes difficult due to the fact that there is no general theory for determining optimal sets of values of primary factors, i.e. output parameters of parts and units comprising an object as well as ensuring the equivalence of object parameters to the quality requirements. This is the main reason why the development of complex systems and objects of vital importance takes several years. To create this theory, one has to overcome a number of difficulties and solve the following tasks: creation of reliable and stable mathematical models that indicate the influence of primary factors on output parameters; determination of accurate solutions when mathematical models are poorly stipulated; and creation of a method of assigning nominal values and tolerances for primary factors with regard to economical, technological and other criteria. All of the above-listed tasks are equally important. The present work is an attempt to describe a solution for this problem. The mathematically formalized aspect of the problem of providing the required level of quality has been called the “multiple inverse problem”

    Methods for testing and optimizing composite ceramics-compound joints by solving inverse problems of mechanics

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    The paper demonstrates methods for testing and selecting composite ceramics-compounds by solving inverse problems of mechanics. A method for the identification of physical and mechanical characteristics of the compound is proposed. The idea of the method is that the studied material is connected with other materials, the characteristics of which are well known and differ from the characteristics of the material. Desired physical and mechanical properties should be considered unknown in the proposed calculation model. Values of the parameters can be measured accurately with experimental methods in the process of product operation. Characteristics of test materials and geometric dimensions of proposed structures are suggested. The solution of the problem of optimizing the tolerances of physical and mechanical characteristics of materials is proposed. In order to ensure the strength of the structure, the geometric dimensions of the composite construction ceramic resistor-compound are suggested

    Calculation of mechanical stresses in adjoint system of electronic component and compound and strength assessment

    Get PDF
    The paper represents mathematical model and formulas developed for project calculations which are applied to sealed electronic units and provide assessing strength of passive electronic components having revolution shape (capacitors, resistors, diodes, pins, etc.). The stress calculation has been produced for materials of resistor and compound in the temperature interval (from –60 to +70°C) along the radius of resistor and compound

    Acoustic emission and methods of its registration (review)

    Get PDF
    Lately a tendency is observed for the steady growth of requirements applied both to construction materials as well as to the methods of estimation of their reliability and quality. Particular attention is paid to the development of new, physically reasonable criteria of structural durability of materials, based on comprehensive study of the phenomena, which form the basis of processes of deformation and fracture. Such approach is supposed to enhance our understanding of the nature of durability and mechanisms of fracture of materials on different scale levels. This is possible only when analysis of these phenomena is accomplished by means of modern physical research methods as well as applying acoustic emission techniques for diagnostics of the fractures

    Calculation of mechanical stresses in adjoint system of electronic component and compound and strength assessment

    Get PDF
    The paper represents mathematical model and formulas developed for project calculations which are applied to sealed electronic units and provide assessing strength of passive electronic components having revolution shape (capacitors, resistors, diodes, pins, etc.). The stress calculation has been produced for materials of resistor and compound in the temperature interval (from –60 to +70°C) along the radius of resistor and compound
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