In this paper, a series of experiments were conducted including testing of the capabilities of composite material as an energy absorber. Composite plate specimens with different corrugation profile have been fabricated and tested under the same condition. The corrugated profiles are: sinusoidal, triangle, and square shape. All these specimens were made of glass fibers using hand layup technique. The corrugated plates are subjected to quasi-static compression load. In addition to that same kind of tested specimens have been modeled and tested using Finite Element Method (FEM). Theoretical and experimental results in a form of energy absorption and specific energy have been recorded. It is found that results of theoretical and experimental tests are almost exactly identical. It has been observed that composite plate with square profile recorded the highest energy absorption and specific energy for theoretical as well as experimental tests.

This paper is devoted to study the effect of crashing of vehicles with concrete blocks that placed around lighting poles. Unexpected dangers takes place if crashing occurs. It may cause death of the driver and passengers, or severe injuries. In order to minimize or eliminate this risk, a system made of corrugated composite material plates have been designed to replace the concrete blocks around lighting poles. This system is made of reinforced fiber glass and it is modeled to crash with a model of car exactly similar to the real one, forming a simulation of car accident. Modeling process takes place using Finite Element Analysis (FEA). ANSYS software utilized for this purpose. Simulation was performed at three different speeds of the vehicle. Results obtained have been recorded in a form of deformed mesh, and contours. The results proved that the new designed system is working perfectly and it has the ability to absorb impact energy caused by car accident. Therefore, by using composite material instead of concrete, risk of death and injuries will minimized or completely eliminated.

 On assiste de nos jours à une disparition progressive de l'écriture dans l'enseignement du français langue étrangère, pour donner la primauté à la communication orale. Il s'en est suivi que, lors des examens écrits, les apprenants font preuve de mauvaises habitudes de pensée: sujets mal saisis, plans de composition flou, argumentation faible, voire incohérente, expression hésitante et imprécise. Ajoutons à cela la manière maladroite quand ils font un résumé de texte, un compte rendu de lecture, un commentaire de texte ou une contraction de texte. Mais, dans l'enseignement de toute langue- maternelle ou étrangère- l'écrit doit faire partie intégrante de l'éducation au langage. C'est justement ce dont on s'est aperçu il y a très peu de temps et qui a déterminé, comme il était prévisible, que l'oral ne tyrannise plus intégralement les classes de français langue étrangère. Sous l'influence de l'approche communicative, un nouvel équilibre sembles s'établir, en perspective, entre les divers "skills" de l'apprentissage, qui ont été longtemps artificiellement cloisonnés. La communication écrite commence à y retrouver une place, limitée certes pour l'instant, mais bien intégrée dans le processus d'apprentissage. L'écrit sous son double aspect- réception et production- lecture et écriture- jouit actuellement d'un regain d'intérêt en didactiques des langues étrangères. Les nouvelles approches de l'écrit s'inscrivent dans le renouveau général théorique et méthodologique, enrichissent des acquis de la sociolinguistique, de la psycholinguistique, de la pragmatique linguistique et littéraire, de l'approche communicative en didactique. 1 Sans revenir à l'opposition normative traditionnelle écrit/oral, qui envisageait l'écrit comme domaine de la belle langue, unique modèle à suivre, on s'attache à dégager la spécificité du code écrit par rapport au code oral dont il ne constitue pas, comme on a pu le soutenir, la simple et imparfaite transcription

This work is focused on nucleation stages during isothermal austenite decomposition in two medium carbon Vanadium Ti / Ti free micro alloyed steels. Isothermal treatment was carried out in the temperature range 350 to 600οC. Metallographic evaluation using optical and scanning electron microscopy (SEM) enabled determination of the nucleation onset phases of isothermally decomposed austenite. Mainly three phases are found to be relevant to this initiation stage of transformation: first is related to grain boundary nucleated ferrite (GBF), second is related to intra-granularly nucleated ferrite (IGF) and the third to pearlite (P). GBF and IGF are divided into the high temperature and the low temperature segments as consequence of either displacive or diffusion nature of transformation. Addition of titanium to V – micro alloyed steel in this work seems to be balanced by a slightly higher C and Mn content, leading to limited effect on nucleation stage of austenite decomposition. The results show that during continuous cooling, onset of pearlite phase can take place. It occurs at temperatures ≥ 500 C°, followed by an incomplete reaction phenomenon. The main characteristics of pearlite is always nucleated on the surface between proeutectoid ferrite and austenite. Incubation time for onset of pearlite decrease with decrease of temperature.