Research

This project is phase 2 of an overarching three-phase project which studies the girth weld failure modes of pipelines. The project 2 evaluates the tensile strain capacity of pipeline under weld strength under- matching condition.

This project carries out experimental investigation of the major contributors to possible pipe failures in the vicinity of girth welds. The current hypotheses have propositioned that the major contributors can be weld strength under-matching, heat affected zone (HAZ) softening, soft root, weld bevel and bending loads. To address the main source of the issue this research studies the tensile strain capacity of welded pipe under various conditions. The main objectives of this research are to:

• determine the best test methods for strength determination of weld metal and HAZ
• conduct single edge notched tension (SENT) tests to determine the R-curve
• experimentally determine the tensile strain capacity of pipes welded using procedures qualified to Tier 1 AS 2885.2 by undertaking full scale pressurised pipe tensile tests and curved wide plate tensile tests
• confirm the suitability of the pipe against the design basis
• provide data points for the validation of FEA modelling in phase 3 of the overarching project.

Industry benefits from the better understanding of tensile strain capacity, and specifically tensile strain capacity under various weld strength matching conditions (over and under matching). This knowledge guides designers and project proponents to optimise pipeline designs whilst still delivering safe and reliable pipelines.

Douglas Proud

Research & Utilisation Program Coordinator

douglas.proud@futurefuelscrc.com