Session: MF-22-01 3D Crack Growth Simulation Using FEA

Paper Number: 123354

123354 - A Simplified Approach Used to Evaluate Equipment Nozzles for Offshore Cyclic Wave Conditions 

The dynamic nature of wave loading in the offshore marine environment creates many fatigue design challenges.  Process equipment (pressure vessels, pumps, heat exchangers, etc.) have been mounted on marine facilities and ships since the dawn of powered ships.  In the last century more and more sophisticated process units have been ship or platform mounted.  This began with the offshore exploration and production of oil and gas in the 1930’s and the advent of nuclear propulsion for ships and submarines in the 1950’s.  The nuclear propulsion industry has addressed the fatigue issues since the beginning.  For oil and gas industry, offshore marine facilities and ships, in particular, which includes barges, fixed leg platform, semi-submersibles, tension leg platforms, SPARS, jack-up rigs and FPSO, fatigue on process equipment may have been mostly ignored.  Today the software used to evaluate marine facilities and ships for dynamic sea states produces fatigue design data (in terms of accelerations and frequencies) that can be used in the evaluation of process equipment.  When evaluating pressure vessels, each vessel will contain many nozzles, each nozzle will contain multiple loading conditions, it may be a very large task to evaluate each nozzle for the applied cyclic conditions.  This paper will present a simplified stress based method used to evaluate the process nozzles for accumulative fatigue damage.  A simple example will be provided on how to develop the allowable stress and how it is applied.  It is possible that this method may also be expanded to cover components other than nozzles.

Presenting Author: Kenneth Kirkpatrick Fluor, Inc.

Presenting Author Biography: Kenneth Kirkpatrick is a Technical Director and Fluor Fellow based out of the Fluor Houston office. Kenneth is currently a Fluor SME and is a 26 year member of the Mechanical Analysis Support Team at Fluor. Kenneth received his Bachelor of Science in Mechanical Engineering from the University of Houston and is currently a Professional Engineer in the state of Texas and Louisiana. Kenneth’s analytical experience includes fatigue, vibration, transient conditions, equipment rigging and structural analysis of vessel components. At Fluor, Kenneth’s primary experience is in ASME Section VIII pressure vessels including all aspects of design, fabrication and construction.

Authors:

Kenneth Kirkpatrick Fluor, Inc.
Barry Millet Fluor, Inc.
Bryan Mosher Fluor, Inc.
James Lu Fluor, Inc
George Miller Fluor, Inc.