Browsing by Author "Ouibrahim, A."

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    Mass transfer in a laminar elongational flow of a drag reducing surfactant
    (Journal of Non-Newtonian Fluid Mechanics, 2002) Boutoudj, M.S.; Ouibrahim, A.; Deslouis, C.
    The mass transfer given by an electrochemical reaction towards a rotating disk in a solution of surfactant having drag reducing abilities exhibits a first order transition. Beyond this transition marked by a significant slump of the mass transfer rate, the flow becomes unsteady and is characterised by an hysteresis cycle. This phenomenon was earlier observed for viscoelastic dilute solutions of linear polymers of high molecular weight and is induced by the elongational strain prevailing in the flow around a rotating disk. © 2002 Elsevier Science B.V. All rights reserved
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    Static and dynamic tearing of thin steel sheets
    (Strength of Materials, 2003) Aberkane, M.; Ouibrahim, A.; Pluvinage, G.; Azari, Z.
    This paper presents the energy analysis of static mode III fracture of thin steel sheets. For dynamic tearing studies we used the Charpy test apparatus. Static tearing tests performed on three types of steel sheets indicate that the linear relationship of Mai and Cotterell is valid for specimens with a leg width W up to 30 mm. In the given range, the specific work of fracture Γe is determined according to the Mai-Cotterell model. The Γe kinetics is studied as a function of the sheet thickness B, radius of curvature ρ, and loading rate V. The modified model includes a linear dependence of ρ versus W. Moreover, we show that variation of the loading rate V from 1 to 300 mm/min has no effect on the specific work of fracture Γe. A slight decrease in the dynamic fracture toughness J0,d has been found. © 2003 Plenum Publishing Corporation