Numerical simulations of pipeline bending tests

Abstract

The paper compares numerical solution with results of experimental solution of pipeline under cyclic loading in elastoplastic domain. The pipeline was subjected to internal pressure and bending moment. Firstly material parameters were estimated (for Besseling model, Chaboche model and Modified AbdelKarim-Ohno model) on the basis of uniaxial loading. The possibility of parameter identification of assumed models using multiaxial tests was tested too. FE program ANSYS was used for all computations. Modified AbdelKarim-Ohno model was implemented by writing own user subrutin in FORTRAN language. Chaboche model usually overpredicts ratcheting under multiaxial stress state in confrontation with experiments, when it is calibrated by uniaxial tests only. Modified AbdelKarim-Ohno model makes possible better calibration for both uniaxial and multiaxial loading cases.

Keywords

• Finite element method
• AbdelKarim-Ohno model
• Cyclic plasticity
• Ratcheting