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Tubular Specimens (tubular + specimen)

Distribution by Scientific Domains

Polymers and Materials Science	60%

Selected Abstracts

Effect of hardness on multiaxial fatigue behaviour and some simple approximations for steels

FATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 8 2009
N. SHAMSAEI
ABSTRACT Constant-amplitude in-phase and 90° out-of-phase axial-torsional fatigue tests were conducted on tubular specimens made from a medium-carbon steel with three hardness levels obtained from normalizing, quenching and tempering and induction hardening to find the effect of hardness on multiaxial fatigue behaviour. In addition, the same loadings were applied on the normalized solid specimens to investigate the effect of specimen geometry on multiaxial fatigue life. Similar fatigue life variation as a function of hardness was found for in-phase and out-of-phase loadings, with higher ductility beneficial in low-cycle fatigue (LCF) and higher strength beneficial in high-cycle fatigue (HCF). Multiaxial fatigue data were satisfactorily correlated for all hardness levels with the Fatemi,Socie parameter. Furthermore, in order to predict multiaxial fatigue life of steels in the absence of any fatigue data, the Roessle,Fatemi hardness method was used. Multiaxial fatigue lives were predicted fairly accurately using the Fatemi,Socie multiaxial model based on only the hardness level of the material. The applicability of the prediction method based on hardness was also examined for Inconel 718 and a stainless steel under a wide range of loading conditions. The great majority of the observed fatigue lives were found to be in good agreement with predicted lives. [source]

Synthetic-aperture technique for high-resolution composite imaging of the inside walls of tubular specimens

INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 4 2004
Hua Lee
Abstract High-resolution survey of the inside walls of tubular specimens is a unique application of synthetic-aperture composite imaging. This article describes the data acquisition process, 3D motion estimation and compensation, image registration, and superposition for the formation of high-resolution composite images from conventional video sequences. Experiment results from the survey of an oil well are used to demonstrate the capability of the technique. © 2004 Wiley Periodicals, Inc. Int J Imaging Syst Technol 14, 167,169, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20020 [source]

Fatigue behavior of filament-wound glass fiber reinforced epoxy composite tubes under tension/torsion biaxial loading

POLYMER COMPOSITES, Issue 1 2007
Dongtao Qi
A study of filament-wound glass fiber/epoxy composite tubes under biaxial fatigue loading is presented. The focus is placed on fatigue lives of tubular specimens under tension/torsion biaxial loading at low cycle up to 100,000 cycles. Filament-wound glass-fiber/epoxy tubular specimens with three different lay-up configurations, namely [±35°]n, [±55°]n, and [±70°]n lay-ups, are subjected to in-phase proportional biaxial cyclic loading conditions. The effects of winding angle and biaxiality ratio on the multiaxial fatigue performance of composites are discussed. Specimens are also tested under two cyclic stress ratio: R = 0 and R = ,1. The experimental results reveal that both tensile and compressive loading have an influence on the multiaxial fatigue strength, especially for [±35°]n specimens. A damage model proposed in the literature is applied to predict multiaxial fatigue life of filament-wound composites and the predictions are compared with the experimental results. It is shown that the model is unsuitable for describing the multiaxial fatigue life under different cyclic stress ratios. POLYM. COMPOS. 28:116,123, 2007. © 2007 Society of Plastics Engineers [source]