ON THE ISSUE OF NUMERICAL MODELING OF NONLINEAR DEFORMATION OF FIELD PIPELINES AT INCREASED TEMPERATURES OF TRANSPORTED MEDIUMS

The article is devoted to one of the problems of creation of a numerical nonlinear model of field pipeline stress-strain state – the problem of selection of approximation for construction of steel deformation diagram on the basis of a minimum dataset, due to absence of experimental tensile diagrams. The relevance of the study is caused by the increased temperature of the transported medium due to the development of deposits of hard-to-recover reserves and the use of thermal enhanced oil recovery methods. On the basis of comparison of the data of scientific articles and standards the influence of the increased temperature of transportation on the values of elastic modulus, yield strength and tensile strength of steel was evaluated. Tables of reduction factors to the considered parameters are formed. A new algorithm of approximation of the steel deformation diagram taking into account the increased temperature for application in modern program complexes is proposed. The results of comparison with the method of A.B. Ainbinder are given.