DUCTILE DAMAGE STUDY OF DEFECTIVE GIRTH WELDS FOR OILGAS PIPELINE - A TAILORED NUMERICAL AND FINITE ELEMENT METHOD CALIBRATION FROM SENT FRACTURE MECHANICS TEST

摘要

In this paper, the evolution of ductile damage in pipe girth welds for offshore pipelines application is studied with the use of Finite Element Analysis. To this purpose, the Gurson-Tvergaard-Needlmen (GTN) model is calibrated and applied to different finite element simulations. Saipem internally developed software, written in Matlab? environment, is used to automatically calibrate the Gurson model from experimental data and run several Finite Element Models of the pipe with different flaws in the girth weld. The objective of this paper is to present and discuss this numerical tool, developed by Saipem coupling a Matlab? GUI and the ABAQUS FE solver. The tool allows speeding up and automatizing the calibration procedure of the Gurson model and making a rapid evaluation in terms of the Crack Driving Force (CDF) for defective girth weld. The tool allows also a quick and efficient model preparation, full FE analysis and postprocessing, with saving of engineering hours.