DEVELOPMENT AND VERIFICATION OF COLD BENDING OFFSET NUMERICAL MODEL

Abstract

For profiling of the pipeline route at the crossed land relief the elastic bend of pipes and curve inserts (branches) which in most cases are made cold flexible pipes are used. When calculating on durability and stability of the section of the pipeline with cold bending offsets (CBO), it is necessary to take into consideration the level of residual stresses and deformations in a branch wall. For the analysis of the residual stress-strain state (SSS) of CBO on stream, in this article the CBO generalized mathematical (numerical) model is developed and also verification on compliance to empirical formulas and the pilot studies is carried out. The developed CBO numerical model allows to define characteristics of the SSS depending on many parameters, such as diameter, pipe wall thick- ness, mechanical characteristics of steel, tap curvature value and a bending angle. Analytical dependences which allow to carry out primary assess- ment of the residual SSS of CBO without application of the program environment of model operation are also presented.