ISSN:
1662-8985
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Casing drilling technique which has been dramatically developing is a revolution inpetroleum industry and has aroused great concerns. The fatigue failure of casing thread connection isa critical issue for using. Therefore, to study the fatigue failure of casing connection is an importantissue for understand the life of casing drilling. For the notched element, how to estimate the life andwhich parameter (equivalent stress, equivalent strain ,or the strain in the root )represent the damageunder fatigue condition is still a problem. The purpose of this paper is to investigate the fatigue life ofnotch element under multiaxial stresses and to find out the damage parameter so as to predict the lifeof notch element. First specimen were machined with the same notch geometer dimension as thecasing thread connection, fatigue tests with tension and torsion loading were carried out by fatiguetest machine , for stress levels designed to obtain S-N lifetime curve. The stress and strain for theconnections subjected to proportional loading were analyzed by elastic-plastic finite element method.The stress-strain state for notched specimens subjected to constant amplitude proportional multiaxialloadings was also calculated and analyzed by the finite element model. Take the equivalent stress,equivalent strain and the strain by FEM in the root into the prediction model, the strain by FEM has agood agreement with the experiment.But the results from the equivalent stress and equivalent strainalso in good agreement with the experiment and is thought to be a simple prediction way
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/40/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.33-37.255.pdf
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