Анализ деформирования внешне ограниченных металлических труб

Abstract

Pipes with an external confinement include structures of the pipe — soil type, in which the modulus of elasticity of the soil is less than that of a metal pipe. The possibility of warping of the pipe wall associated with a local loss of pipe stability when compressed from the medium is investigated. It is assumed that the soil exerts dynamic pressure and local force pressure on the pipe, which is characteristic of seismic loads. A software-digital approach is proposed for calculating the separable extended structure of pipe — soil, which focuses on the construction of 3D finite element models of the structure and calculations in the LS-DYNA software package in a dynamic formulation. The structure is divided into three-dimensional TSHELL finite elements, the pipe material is taken as elastic-plastic, and the medium is linear-elastic. On the side contact surface between the pipe and the medium a normal unilateral constraint is taken, there are no tangential interactions. Calculations are carried out for two types of loading: swaging and swaging with additional local impact. A comparative analysis of the obtained stress states is performed. The appearance of plastic deformations in the pipe is noted. The calculations according to the known two-dimensional calculation schemes of the pipe — soil structure are given.