EXPLOSION OF IRON HYDROGEN STORAGE CONTAINERS 120 YEARS AGO – Investigations Revisited

An interesting  publication in “Engineering Failure Analysis” available online 24 April 2014.

A nearly authentic translation of Adolf Martenś investigation report on the failure of numerous hydrogen storage cylinders is provided.

  • Explosion of the iron containers caused immense destruction on the air field Berlin-Tempelhof in 1894.
  • The translation reveals very detailed experimental procedures and at that time quite modern materials testing technologies.
  • The importance of Adolf Martens as a pioneer in conducting failure investigations becomes obvious.

Acceder article

An investigation into failure analysis of interfering part of a steam turbine journal bearing

A new Case Studies in Engineering Failure Analysis. Journal 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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Caractérisation d’assemblages par collage

Vous avez besoin de caractériser la tenue mécanique de votre assemblage collé pour valider le choix de votre colle et du process de fabrication associé et vérifier la conformité de produit au cahier des charges,   optimiser ou sécuriser vos cycles de production.Les multiples compétences des experts du Cetim en collage, fatigue mécanique et calcul du Cetim vous font bénéficier de leur expérience du milieu industriel pour vous aider à innover et fiabiliser votre produit.

Acceder article

La thermographie infrarouge active s’impose

La thermographie infrarouge active consiste à soumettre l’élément à contrôler à une excitation extérieure maîtrisée et à y analyser la propagation de la chaleur : les perturbations visualisées révèlent alors les éventuels défauts surfaciques ou subsurfaciques tels que fissures, délaminages, corrosion, inclusions d’eau ou d’éléments étrangers, etc. La formation du Cetim, sur deux jours, débute par la présentation des principes physiques de la méthode, les matériels utilisés, les types d’excitation, les logiciels de traitement d’image, les paramètres d’influence, etc.

La société Otecmi, a souhaité se former à la thermographie infrarouge active. Une technique bien adaptée à la détection des défauts dans les composites…

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Investigation of Minor Leakage in a Fuel Oil Return Line

A small fuel oil return line of a stationary gas turbine engine failed by high cycle fatigue cracking. In the metallurgical root cause investigation, performed by the original equipment manufacturer’s laboratory, it was determined that insufficient support of the fuel line and the ensuing vibration led to dynamic alternating bending stresses, that had their maximum immediately adjacent to the connector weld of the flange…………. Read more

Microscopy and C-Scan Techniques in the Study of Defects of CFRP Composites

A new article published in Practical Metallography: Vol. 51, No. 5, pp. 353-366.

Carbon Fiber Reinforced Plastic composites were fabricated through vacuum resin infusion technology by adopting two different processing conditions, viz., vacuum only in the first and vacuum plus external pressure in the next, in order to generate two levels of void-bearing samples. They were relatively graded as higher and lower void-bearing ones, respectively. Microscopy and C-scan techniques were utilized to describe the presence of voids arising from the two different processing parameters……….. Read more

FLEXURAL FATIGUE FAILURE ANALYSIS OF GLASS POLYESTER UNIDIRECTIONAL ANGLE PLY COMPOSITE LAMINATE

ijerstThis paper, published in « International Journal of Engineering Research and Science & Technology« , presents a study of the fatigue failure behavior of unidirectional angle ply composite laminate. Today a lot of research is directed to understand the fatigue failure behavior of laminated composites. These materials usage is increasing in all sorts of engineering applications due tohigh specific strength and stiffness, low weight and corrosion resistance. Fibre reinforced composite materials are selected for weight critical applications, due to good rating as per the fatigue failure is concerned and these materials are anisotropic in nature. The failure behavior made the study of these materials complicated………….

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FAILURE ANALYSIS OF RE-BARS DURING BENDING OPERATIONS

Thermo-mechanical treated(TMT) rebar is suitable material for reinforcing concrete structures on accounts of similarity in thermal expansion, ability to bond well with concrete and, above all the ability to shoulder most of the tensile stress acting on the structure and also steel manufacturing industry has successfully developed a corrosion-resistant variety of rebar for the construction industry. As the TMT is the finish product thus proper control of rolling parameters and water box is needed to achieve adequate property. Water box plays an important role for achieving the final structure and property of the rebars.Water box is responsible for outer rim formation and which helps to achieve the yield strength of the material. The present paper highlights failure investigation of a failed rebar during bending operations. From Fractography and microstructural analysis it is confirmed that the rebar sample failed in brittle manner due to through harden martensitic structure and which indicates that there is some anomaly in water box resulting in these premature failures.

Source : Case Studies in Engineering Failure Analysis

Mécanique de la rupture fragile et de l’endommagement : approches statistiques et probabilistes

Cet ouvrage écrit par Jacques Lamon et édité par la Librairie Lavoisier, 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.  Lire la suite

Corrosion des pièces soudées : essais sur mobilier

Cet ouvrage présente les résultats d’une campagne d’essais réalisée à la demande de la commission « Mobilier » du Cetim sur les facteurs influents dans le développement de la corrosion des pièces soudées.

Deux procédés de soudage ont été comparés et des défauts volontaires ont été introduits au niveau des soudures pour analyser leurs effets en matière de corrosion après application de la peinture. Une pièce présentant des points de soudure et des zones difficiles d’accès a également été étudiée.

Cet ouvrage est réservé aux cotisants de la profession.  Corrosion mobiliers metal