CRANKSHAFT FAILURE DUE TO FATIGUE—A REVIEW

couvertureAn interresting paper published in « International Journal of Mechanical Engineeering and Robotics Research« . This paper focuses on the failure of crankshaft due to fatigue which are put into service in several aplications. Crankshaft is important part in al types of engines employed in aplications like aircraft, reciprocating compresor, marine engine, vehicle engine as wel as diesel generator. The failure of crankshaft is due to fatigue resulting into cracks on the surface of crankshaft and efect of residual streses due to filet roling proces. The motivation behind this paper is to study how fatigue phenomenon leads to the failure of the crankshaft.

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Publicités

Fracture mechanisms of failed IN-738LC gas turbine blades

An interesting  paper in « Case study in Engineering Failure Analysis » published on ScienceDirect.com. This paper outlines the problem of blades failure occurred because of excessive temperature exposure. Nickel based superalloys are widely used as gas turbine blade material. They suffer from microstructural instabilities and environmental damages. Creep properties of alloy was deteriorated by γ‘ particles dissolution.

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Brittle fracture of a grade E cast steel knuckle

A new paper in « Case study in Engineering Failure Analysis » published on ScienceDirect.com. This paper investigated the brittle fracture mechanism of a grade E cast steel knuckle that is one of the key components of the coupler for railway wagon.

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A failure study of the railway rail serviced for heavy cargo trains

rail fractureA paper published in« Case study in Engineering Failure Analysis »In this case study, a failed railway rail which was used for heavy cargo trains was investigated in order to find out its root cause. The crack is supposed to be initiated from the weaker ferrite networks. Given all of that, the failed railway rail is considered to be caused by overload. It is of great importance to improve the welding technology, and control the load of train in order to prevent similar failure in future.

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Study on the creep behavior of bonded metallic joints

a test specimenBonded joints have been used as the main alternative to join components made of different materials or not. Literature shows that although prior studies focused on the characterization of several mechanical properties related to joints, little is known about the creep behavior of bonded joints. This work  studies the behavior of single-lap joints (SLJ) made of metallic substrate and bonded with epoxy and polyurethane adhesives. Results show that, for long term applications, the average tensile strength isn’t enough to guarantee project safety. An initial model for the creep behavior of bonded joints is proposed.

Cliquez pour télécharger le texte complet de l’article paru via :  http://www.appliedadhesionscience.com/content/pdf/2196-4351-2-8.pdf

Mécanique de la rupture fragile et de l’endommagement : approches statistiques et probabilistes LAMON Jacques: Librairie Lavoisier

A LavoisierCet ouvrage de Jacques Lamon a été publié chez Lavoisier en septembre 2007. Il analyse le phénomène de la rupture fragile, son caractère aléatoire et les conséquences de la présence de populations de défauts dans les matériaux. Il présente les approches stochastiques de la rupture fragile et les méthodes de prévision sous des conditions diverses. Il étudie divers modèles tels que celui de Weibull et des approches plus fondamentales qui reposent sur la loi de distribution des défauts et le concept de contrainte élémentaire multiaxiale. Ce livre s’adresse à tous ceux qui s’intéressent à la rupture fragile, aux approches probabilistes, aux prévisions, aux matériaux fragiles quels qu’ils soient céramiques, béton, fibres… à leur combinaison au sein de composites, de multicouches, ou de structures. Il aborde les aspects théoriques mais aussi expérimentaux. Il est illustré d’exemples et de cas d’étude.

Pour en savoir plus : LAMON Jacques: Librairie Lavoisier.

Interfering part of a steam turbine journal bearing

bearing part frettingJournal bearings as so sensitive parts of steam turbines are very susceptible to failure through different mechanisms of wear, fatigue and crush during service conditions. Failure occurring through these mechanisms lead to turbine completely shut down as a result of interfering in working conditions of bearing different parts. In this research, failed interfered part of a journal bearing related to a 320,000 kW steam turbine was examined.The studies were revealed that the bearing part loosing and inappropriate clearance can produce relative displacements under cyclic gradient loading. This condition was detrimental for the service life of turbine journal bearing via failure through fretting fatigue mechanism.

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Failure analysis of a pelton impeller

A new topic on « http://www.sciencedirect.com/« .This paper, published in « Engineering Failure Analysis« , presents the analysis of a 16-bucket Pelton impeller from a hydroelectric plant in Colombia, a plant with two turbo generators with a nominal capacity of 2.33 MW each. Multiple cracks were detected one year subsequent to geometry reconstruction welding repair.

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Case Studies in Marine Concentrated Corrosion

A new paper in « Case study in Engineering Failure Analysis » published on ScienceDirect.com. This paper outlines the problem and analysis techniques in three exemplar case studies of marine concentrated corrosion. The paper includes an outline of some of the relevant literature relating to the use of these modern techniques in identifying marine corrosion products.

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