Wall Thickness Analysis Of Pressure Vessel

pressure vesselAn article published in International Journal of Advance Foundation And Research In Science & Engineering, on March 2015.

Limited work has been reported on thermal & pressure stresses developed in welded portion of pressure vessel as well as in wall of the pressure vessel. Upto most of the literatures works on analytical solution to determine the stress distribution in a multilayered composite wall pressure vessel subjected to an internal pressure and a thermal load, based on thermo-elastic theory. In the solution, extra pressure was proposed to emulate the effect of the whole closed ends of the pressure vessel. To validate the analytical solution, the stress distribution of the pressure vessel was also computed using finite element (FE) method. It was found that the analytical results were in very good agreement with the computational ones, and the effect of thermal load on the stress distribution. The proposed analytical solution provides an exact means to design composite pressure vesses and investigates ultrasonic method in stress measurement through thickness of a pressure vessel. Hoop and axial residual stresses are evaluated by using different frequency range of ultrasonic transducers analyses it for longer life.

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A failure Study of a locking compression plate implant






An interesting  paper in « Case study in Engineering Failure Analysis » published on ScienceDirect.com. In this case study a failed locking compression plate was investigated. Such plating systems are used to provide the stability to fractured bone and fixation. The locking compression plate had been separated in two pieces. One of the fracture surfaces from the failed component was investigated for surface topographical features. The visual, optical and scanning electron microscopy results indicated the presence of beach marks, intermetallic inclusions, corrosion pits and striations indicating fatigue crack propagation and overload failure. Some corrosion damage also was documented on the fractography. This case study shows that corrosion may have initiated fatigue crack which grew by the activities of daily living causing the failure.

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Evaluer les dommages par corrosion par piqûres dans des trains d’engrenages planétaires

sun gear with pittingLa boîte d’engrenages planétaires est un mécanisme crucial dans les systèmes de transmission d’un hélicoptère. Une défaillance dans un train d’engrenage serait une source de risque énorme pour les opérations. L’article présente une méthode d’évaluation des degrés des dommages causés par la corrosion par piqûres, qui intègre un modèle physique de simulation par générateur de signaux. La méthode proposée a d’abord été calibrée par des tests d’injection de défauts dans les données, et ensuite validée a l’aide des données d’autres tests sur des trains d’engrenage. Les résultats des estimations des données de ces tests correspondent avec les résultats actuels, démontrant ainsi l’efficacité et l’exactitude de la méthode, et procurant des nouvelles méthodes de modélisation et d’évaluation pour une meilleure surveillance des conditions.

Article publié dans : Transactions of the Canadian Society for Mechanical Engineering, Vol. 35, No. 3, 2011