Le BEA fait appel aux experts Analyse de Défaillances du Cetim.
BEA – Une analyse sur pièces composites
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Archives du mot-clef cas concrets
Stress corrosion cracking of full sized rockbolts
An article published in « International Journal of Rock Mechanics & Mining Sciences – 81 (2016)« .
Previous studies had identified that a testing protocol was required to examine stress corrosion cracking (SCC) of full sized rockbolts under simulated in situ conditions. It was found that SSR testing provided an appropriate analogue for examining rockbolt susceptibility to SCC and was thus used to examine the effect of grit blasting, galvanising and varying steel grades on the SCC resilience of rockbolts. Of these, 300 grade steel and galvanising provided the most promising resistance to SSC, while grit blasting provided a 40% improvement in resistance compared to untreated HSAC 840 grade rockbolts.
Des joints qui durent vraiment plus longtemps
Étanchéité, nettoyabilité, endurance… Les nouveaux joints sélectionnés par Serac pour l’étanchéité dynamique de haut de cuve alimentaire durent huit à dix fois plus longtemps. Quant aux coûts, ils sont divisés par deux.
Pour en savoir plus, lire l’article dans le document joint.
Failure investigations of a 900 KV bil trench cota bushing
A case study of failure discussed in the 82 nd International Conference of Doble Clients.
The discussion of this paper will focus on the H1 Trench COTA bushing, which failed after field maintenance handling that would not normally be expected to have a negative effect on a bushing. Following the failure, the top air side porcelain was found ruptured and missing; the bottom insulator was fractured into a number of pieces. The H2 and H3 bushings from this transformer, which were identical Trench type bushings, were also removed and disassembled for inspection to help identify a possible root cause of the H1 bushing failure.
Fatigue Failure of Aluminium Alloy Piston
An article published in International Research Journal of Engineering and Technology (IRJET), Volume: 03 Issue: 04 | Apr-2016.
An analytical study was performed about piston failure by fatigue. Fatigue cracks are initiated and propagated by the action of mechanical and high temperature loading conditions which induces cyclic stresses in the piston material. Various proposals and solutions are presented so that necessary care can be taken to prevent piston failure in future.
Catastrophic failure of a carbon steel storage tank due to internal corrosion
A case study of failure analysis published in « Case Studies in Engineering Failure Analysis« , october 2013.
Catastrophic failure of a 10 m high, 8 m diameter steel storage tank containing approximately 350 m3 of waste solvent led to a significant environmental incident in 2009. An investigation was carried out to establish the root cause and to learn lessons that might prevent a reoccurrence.
Failure analysis of a high strength low alloy steel pressure vessel
A Failure Analysis published in « Case Studies in Engineering Failure Analysis » october 2013.
High stre
ngth low alloy (HSLA) steel with a nominal composition of 0.15C–1.25Cr–1Mo–0.25V is being extensively used in space programme. Owing to its ease of fabrication and welding, a tank was fabricated out of this alloy. The tank is used to contain strontium per chlorate which on combustion develop secondary thrust, effectively used during attitude control of satellite launch vehicle. During one of the routine qualification tests, a tank had failed at an internal pressure of 109 bar, against a designed proof pressure of 120 bar.
Failure was initiated from long seam weld of a cylindrical shell and propagated into the parent material thereafter. Detailed metallurgical investigation has been carried out to understand the cause of failure. This paper brings out the detail of investigation carried out.
Adapter les dentures aux déformations
Autoclaves industriels : contrôler sans démonter
L’expertise de vannes de barrage passe les frontières.
Les nombreuses années d’expertises d’ouvrage pour le compte du producteur d’énergie électrique historique en France n’empêchent pas les experts du Cetim d’effectuer ce type de prestation à l’étranger. Exemple au Maroc. Leur mission : le diagnostic de l’état des cinq vannes de crue d’un barrage. L’opération s’est déroulée en deux étapes. D’abord, un contrôleur a passé cinq jours sur place pour réaliser l’ensemble des inspections et mesures nécessaires. Ensuite, l’ensemble de ces données a été exploité pour paramétrer le modèle des vannes de crue, afin de déterminer par simulation si elles supporteraient l’ensemble des sollicitations auxquelles elles peuvent être soumises. A noter, c’est la première fois que Tractebel Engineering, filiale d‘Engie, fait appel au Cetim pour profiter de sa double compétence dans le domaine du contrôle sur site et de la simulation par éléments finis.
