56 research outputs found

    Creep damage processes in cyclically loaded structural members

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    The paper contains the description of the cyclic creep damage law that allows to estimate the long-term strength of metallic materials in wide range of frequencies of loading and heating. Asymptotic methods and procedures of averaging in a period were used for deriving the damage laws

    Creep and damage in shells of revolution under cyclic loading and heating

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    Creep of cyclically loaded thin shells of revolution and their fracture due to creep and fatigue mechanisms are studied. Creep-damage equations for steels and nickel-based alloys are built by the use of scalar damage parameter. Constitutive equations were derived using the method of asymptotic expansions and averaging over a period of cyclic loading. The cases of fast and slow varying of temperature and loading are regarded. General problem statement and method for solution of creep problems at cyclic loading are presented. Strain–stress state in shell structures is determined by the use of homemade FEM creep–damage code, where the finite element of conical shell is used. Results of creep–damage problem for conical panel are discussed

    High temperature creep and damage accumulation in cyclically loaded axisymmetrical bodies of revolution

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    The paper presents the constitutive equations as well as the data of numerical simulation of creep-damage problems of cyclically loaded and heated axisymmetrical structural members. The procedure of constitutive equations deriving is discussed. The experimental and numerical data have been obtained for cyclically heated specimens made from high quality steel were compared in order to verify the flow rule and damage parameter equation. The problem of creep and damage accumulation in the nipples of the regenerator for catalytic cracking of petroleum was analyzed with consideration of different temperature cycle parameters

    Creep and damage in shells of revolution under cyclic loading and heating

    Get PDF
    Creep of cyclically loaded thin shells of revolution and their fracture due to creep and fatigue mechanisms are studied. Creep-damage equations for steels and nickel-based alloys are built by the use of scalar damage parameter. Constitutive equations were derived using the method of asymptotic expansions and averaging over a period of cyclic loading. The cases of fast and slow varying of temperature and loading are regarded. General problem statement and method for solution of creep problems at cyclic loading are presented. Strain–stress state in shell structures is determined by the use of homemade FEM creep–damage code, where the finite element of conical shell is used. Results of creep–damage problem for conical panel are discussed

    High temperature creep and damage accumulation in cyclically loaded axisymmetrical bodies of revolution

    Get PDF
    The paper presents the constitutive equations as well as the data of numerical simulation of creep-damage problems of cyclically loaded and heated axisymmetrical structural members. The procedure of constitutive equations deriving is discussed. The experimental and numerical data have been obtained for cyclically heated specimens made from high quality steel were compared in order to verify the flow rule and damage parameter equation. The problem of creep and damage accumulation in the nipples of the regenerator for catalytic cracking of petroleum was analyzed with consideration of different temperature cycle parameters

    Nonlinear vibrations and long-term strength of turbine blades

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    The method of a durability estimation of rotating turbomachinery blades at forced flexural-flexural-torsional vibrations is offered. The method is based on the methods of Continuous Damage Mechanics and the accurate strain analysis of the pre-twisted blades at the nonlinear vibrations with moderate displacements. The method to solve the strain analysis problem and turbomachinery blades high-cycle fatigue damage estimation as a result of nonlinear vibrations is presented

    The Scientific and Social Activity of Professor N. N. Saltykov in Russia in 1894–1919

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    The scientific and social activity of Professor N. N. Saltykov in Russia in period 1894–1919 is presented

    Numerical Calculations of Creep Damage at Cyclic Loading by Use of Tensor Damage Parameter Model

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    Creep of cyclically loaded bodies and their fracture due to creep mechanisms are studied. Creep damage equations are built by use of tensor parameter for titanium alloy. Similar equations were derived for stress cyclic varying using the method of asymptotic expansions and averaging in a period. 2d plane stress problems were solved by FEM and fields of stress, strain, displacement, damage parameter components as well as time to rupture values were obtaine
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