Notched Components (notched + component)

Distribution by Scientific Domains


Selected Abstracts


Fatigue Design of Notched Components with Stress Gradients and Cyclic Plasticity

ADVANCED ENGINEERING MATERIALS, Issue 9 2009
Mahaman Habibou Maitournam
This paper shows that the fatigue strength of notched specimens under cyclic loading can be simply and accurately estimated by using elastic-plastic computations and by averaging the stress over a critical volume obtained by an optimisation process, minimizing the dispersion between experiments and simulations. The Dang Van high-cycle fatigue criterion is considered. Fatigue tests (tension-compression, bending and torsion) carried out by CETIM, are used to calibrate the critical volume. [source]


Fatigue notch sensitivity of steel blunt-notched specimens

FATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 7 2002
M. D. CHAPETTI
ABSTRACT The notch sensitivity of three steels with similar plain fatigue limits was analysed and modelled. The analysis was made by using a model previously derived which estimated the fatigue limit of blunt notched components by means of the parameter ktd defined as the stress concentration introduced by the notch at a distance d from the notch root surface equal to the distance between microstructural barriers. The analyses show how the first two or three microstructural barriers define the fatigue limit and the fatigue notch sensitivity of blunt notched specimens. [source]


Deformation analysis of notched components and assessment of approximate methods

FATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 11 2001
Y. Jiang
Finite element modelling was conducted on notched members subjected to proportional and non-proportional loading. A recently developed cyclic plasticity model capable of accurately describing cyclic material behaviour was implemented into a finite element code. A plate with a central hole and a shaft with a circumference groove were studied. Approximate methods for the notched problems were critically evaluated using the finite element results. [source]


Influence of the remelting process on the fatigue behavior of electron beam irradiated UHMWPE

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2006
J. A. Puértolas
Abstract Electron beam irradiation at doses below 150 kGy is a widely used technique to obtain highly crosslinked ultra-high-molecular-weight polyethylene (UHMWPE). Its current use in total joint replacement components may improve wear resistance and decrease UHMWPE particle debris. However, currently used post-irradiation thermal treatments, which aim to decrease the free radicals within the material, introduce microstructural changes that affect UHMWPE mechanical properties, particularly the fatigue strength. This influence may be crucial in total knee replacements, where fatigue-related damage limits the lifespan of the prosthesis. Therefore, more studies are required to understand UHMWPE fatigue after current crosslinking protocols. This study was planned to evaluate the influence of UHMWPE remelting after irradiation on the material fatigue resistance. The remelting was achieved at 150°C for 2 h on UHMWPE previously irradiated at 50, 100, and 150 kGy. Fatigue evaluation included short-term tests under cyclic tensile stress with zero load ratio, R = 0, and 1 Hz. In addition, stress-life testing was performed using 12% yield as the criterion for failure. Near-threshold fatigue crack propagation experiments were also performed at a frequency of 5 Hz, and crack length was measured in nonthermally treated and remelted irradiated UHMWPE. Crystallinity percentage was calculated from DSC measurements. The results pointed out that irradiation positively contributed to total life analysis, but the further remelting process decreased the flaw initiation resistance. On the other hand, both processes negatively affected the fatigue resistance of notched components. From a clinical point of view, the results suggest that the material fatigue behavior should be carefully studied in new UHMWPE to avoid changes related to material processing. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006 [source]