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

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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