Գազատրանսպորտային համակարգերում էլեմենտների լարվածային վիճակի հետազոտումը

Abstract

It is shown that the responsible nodes and elements of gas transmission systems generally operate under conditions of cyclic stresses. In order to determine the fatigue resistance of the elements, the fatigue tests of steel samples were carried out on a special fatigue machine, which is reproducing the specified stress state. Parametric equations of fatigue lines were obtained, according to which the limit stresses were determined over the entire range of cycles. In the three-dimensional coordinate system the limit stresses surfaces are constructed and the influence of tangential stresses in the specified range of cycles was identified. Summary, the tangential stresses simultaneously initiate two opposite actions, the final result of which depends on the number of cycles and on the degree of stress concentration. It is proposed to create a new calculation technique for assessment the fatigue resistance parameters under variable loading, as well as for determining the values of limit stresses and for durability.