Fatigue Lifetime Prediction for Oil Tube Material Based on ABAQUS and FE-SAFE

Abstract

A novel approach for the fatigue life prediction based on the combination of FE simulation using ABAQUS and fatigue analysis in FE-SAFE has been proposed in this paper. A phenomenological constitutive equation and an exponential ductile damage model were first developed using an iterative method to describe the whole deformation process including fracture of plate specimen prepared from N80 oil tube. In addition, fatigue tests for N80 specimen were conducted at a stress ratio R = 0.1 and at a loading frequency of 15 Hz, in which the maximum applied stress was chosen as 500, 540 and 600 MPa. The fatigue test data was further analyzed using Kolmogorov–Smirnov (K–S) tests, and results show that the logarithm fatigue life follows normal distribution. The S–N curve for N80 oil tube materials was established based on the fatigue test results and statistical analysis. The results of stress distribution in N80 plate specimen from FE simulation and the experimentally determined S–N curve were imported to FE-SAFE for the prediction of fatigue life. Good agreement has been achieved between the predicted fatigue life using the proposed approach and experimental results.