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Le blog de l’European Structural Integrity Society

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Il s’agit du blog de l’ESIS (European Structural Integrity Society). La mission de iMechanica est :

  1. d’utiliser l’Internet pour améliorer la communication entre les mécaniciens
  2. d’ouvrir une voie pour faire évoluer en ligne toutes les connaissances des mécaniciens

iMechanica est hébergé sur un serveur à la Harvard School of Engineering et sciences appliquées . Il est administré par des bénévoles, mécaniciens, tout comme vous . iMechanica est libre: les écrivains sont libres de poste, et les lecteurs sont libres de lire.

Pour en savoir plus : http://imechanica.org/node/74

ESIS- EUROPEAN STRUCTURAL INTEGRETY SOCIETY

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ESIS's picture

http://www.esisweb.org/

Declamation of aims and activities

The aim of ESIS is to continuously develop a knowledge base relating to all aspects of Structural Integrity with the objective of improving the safety and performance of engineering structures, components, systems and their associated materials.

Specifically:

  1. To foster research and collaboration regarding the prevention of failure, by fracture or other physical phenomena, of engineering structures, components, systems and materials.
  2. To encourage interdisciplinary research into the physical behaviour of engineering structures, components, systems and their associated materials.
  3. To develop and assess new testing methods, numerical methods, and engineering estimation methods for structural integrity assessments.
  4. To improve engineering designs.
  5. To improve manufacturing, inspection and maintenance procedures.
  6. To disseminate knowledge, by means of scientific publications, technical conferences, seminars, workshops, procedure documents, and to refer new knowledge and developments to national and international code making bodies, including CEN and ISO, where relevant.
  7. To educate young engineers and scientists in structural integrity matters.

Fracture Blog

Promoting and intensifying this aim is what we want to achieve through a new blog that ESIS will manage on Imechanica:

http://www.imechanica.org/blog/23810

for discussing some of the papers which appear in Engineering Fracture Mechanics. Its editors, Profs. Karl-Heinz Schwalbe and Tony Ingraffea,fully support this initiative.

Une revue en anglais consacrée à l’analyse de défaillances

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Engineering Failure Analysis

Published in Affiliation with the European Structural Integrity Society

Engineering Failure Analysis publishes original, high quality research papers, communications, and occasional review articles describing the analysis of engineering failures and related studies.
Papers…

Lien : Engineering Failure Analysis – Elsevier.

Failure Analysis : Analysis of the drive shaft fracture of the bucket wheel excavator

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ScienceDirect – Engineering Failure Analysis : Analysis of the drive shaft fracture of the bucket wheel excavator.

Mile Savkovića,, Milomir Gašića, Dragan Petrovića, Nebojša Zdravkovića, Radmila Pljakićb

a University of Kragujevac, Faculty of Mechanical Engineering Kraljevo, Dositejeva 19, 36000 Kraljevo, Serbia
b Laboratory for Testing of Materials High School Trstenik, Radoja Krstića 19, 37240 Trstenik, Serbia

Abstract

Drive in most bucket wheel excavators (BWE) is accomplished through its electric motor, cardan shaft and planetary gearbox. In the BWE SchRs630/6×25, the planetary gearbox is cantilevered at the end of the hollow shaft which transmits the torque through the sprocket to the caterpillar track chain. In this BWE, a the drive shaft fracture occurs at the point of support on the penetration side.

Experimental testing of the chemical composition and mechanical properties of the material of the shaft and metallographic inspections of the fracture surface by means of electronic and light microscopes carried out in the first part of the paper have shown that there are no significant inhomogeneities and errors in the material of the shaft and that they do not cause damage. Further, the analysis of results referring to the mechanical properties and chemical composition of the repaired shaft at the point of welding, and particularly in the transition zone, shows that they considerably deviate from those prescribed for the material used. Significant inhomogeneity of the material, occurrence of cracks as well as the difference in the microstructure appear in this zone, which is the cause of shaft damage.

The second part of the paper presents the FEM analysis of effects of the cantilever type of support of the planetary gearbox and stress concentration at the point of support due to inadequate finishing, which caused the occurrence of an initial crack. The user unsuccessfully tried to eliminate this weakness by repair welding of the shaft.

Highlights

► The cause of the drive shaft fracture of the BWE SchRs630/6×25 was examined. ► The shaft fracture did not occur due to any errors in the material. ► The cause of the initial crack is inadequate machining of the shaft. ► The cause of the shaft fracture is the badly performed repair welding process.

Analyse de défaillance d’un cas de fatigue thermique sur un laiton moulé

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Dhouha Melloulia, , Nader Haddara, Alain Kösterb, Hassine Ferid Ayedia

a Laboratory of Industrial Chemistry and materials, National Engineering School of Sfax, Box1173, W3038, Sfax, Tunisia
b Centre des matériaux Pierre Marie Fourt, Ecole des Mines de Paris

Abstract

This research has been conducted to elucidate the mechanisms of brass die casting failure. A die was examined and we have evaluated the causes of crack failure mechanisms after use in brass die casting. The dominating failure mechanism in the investigated die was thermal fatigue cracking. Crack initiation is associated to accumulation of the local plastic strain that occurs during each casting cycle. The crack growth is facilitated by a number of elements: oxidation of the cracks’ surfaces, filling of brass and softening of the die material.