R. Rolovic et Sm. Tipton, Multiaxial cyclic ratcheting in coiled tubing - Part II: Experimental program and model evaluation, J ENG MATER, 122(2), 2000, pp. 162-167
Citations number
2
Categorie Soggetti
Material Science & Engineering
Journal title
JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME
An experimental program was conducted to evaluate the plasticity model prop
osed in a separate paper (Part I). Constant pressure, cyclic bend-straighte
n tests were performed to identify material parameters required by the anal
ytical model. Block pressure, bend-straighten tests were conducted to evalu
ate the proposed model. Experiments were performed on full-size coiled tubi
ng samples using a specialized test machine. Two commonly sued coiled tubin
g materials and four specimen sizes were subjected to load histories consis
ting of bending-straightening cycles with varying levels of internal pressu
re. It was observed that cyclic ratcheting rates can be reversed without re
versing the mean stress, i. e., diametral growth of coiled tubing can be fo
llowed by diametral shrinkage even when the internal pressure is kept posit
ive, depending on the loading history. This material behavior is explained
in the context of the new theory. The correlation between the predictions a
nd the test data is very good. [S0094-4289(00)00502-8].