Analytical and Experimental Determination of FML Stiffness and Strength Properties.

The paper presents application of analytical methods of determining the mechanical properties of Fibre Metal Laminates. Chosen micromechanical methods were employed to predict elastic moduli and strength of FML panels. Prediction was conducted on two levels i.e. micromechanics where properties of a single composite lamina (prepreg) were analyzed, and macro–mechanics to determine properties of a full FML hybrid material. The properties of a single GFR lamina were predicted by Rule of Mixture Method (ROM), inverse Rule of Mixture Method with correction factor, Halpin Tsai Method, Tsai Method and Wilczynski Method application. Properties of full 3–2 FML lay–up were determined using the Rule of Mixtures. Analytical results were verified by experimental tests. Tensile and bending test were performed on rectangular standard coupons of 3–2 FMLs

Static and Dynamic Thermomechanical Buckling Loads of Functionally Graded Plates.

In the paper the buckling phenomenon for static and dynamic loading (pulse of finite duration) of FGM plates subjected to simultaneous action of one directional compression and thermal field is presented. Thin, rectangular plates simply supported along all edges are considered. The investigations are conducted for different values of volume fraction exponent and uniform temperature rise in conjunction with mechanical dynamic pulse loading of finite duration

Buckling strength improvements for Fibre Metal Laminates using thin-ply tailoring

The buckling response and load carrying capacity of thin-walled open cross-section profiles made of Fibre Metal Laminates, subjected to static axial compression loading are considered. These include thin-walled Z-shape and channel cross-section profiles adopting a 3/2 FML lay-up design, made of 3 aluminium layers. The objective of the investigation is the comparison of standard thickness Fibre Reinforced Plastic layers versus thin-ply material technology. Whilst thin ply designs differ only by the layer thickness, they offer an exponential increase in stacking sequence design freedoms, allowing detrimental coupling effects to be eliminated. The benefit of different hybrid materials are also considered. The comparisons involve semi-analytical and finite element methods, which are validated against experimental investigations

Lagunage naturel de lixiviat de décharge

Dans le cadre d'un traitement par lagunage naturel des lixiviats d'une décharge d'ordures ménagères broyées, nous avons procédé au cours d'un cycle annuel (mai 1998 à mai 1999) à des analyses biologiques et physicochimiques des eaux à l'entrée (lixiviat brut), dans les quatre bassins successifs et à la sortie du dispositif (lixiviat traité) avant son rejet dans le milieu récepteur (ruisseau Mont Bonnet). L'évolution spatiotemporelle de la qualité des lixiviats a été approchée par le suivi des fluctuations saisonnières de divers paramètres (température, conductivité électrique, pH, oxygène dissous, potentiel redox, chlorures, fer, manganèse, nickel, zinc, azote total, phosphore total, ammonium, DBO, DCO et chlorophylle a). Les résultats montrent deux périodes de dysfonctionnement de la station durant l'année. Un dysfonctionnement estival marqué par une chute du rendement épuratoire du fer, du manganèse et de la DBO, sous l'effet d'une diminution du potentiel redox et du surplus de matières organiques autochtones. Le deuxième dysfonctionnement, observé en hiver et au début du printemps, est caractérisé par une chute des rendements épuratoires pour l'ensemble des éléments chimiques suivis. Cette chute des rendements épuratoires est vraisemblablement liée à la diminution importante des valeurs de pH durant cette période.The Etueffont municipal landfill waste (Northeast of Belfort, France) possesses a mode of exploitation by grinding wastes without compaction, to facilitate the aerobic degradation. This technique leads to a leachate production. The leachate was treated by natural lagoons consisting of 4 decantation basins then released in the brook (of Mont Bonnet). Efficiency of the epuration was estimated by calculation the net budget of elements (=Input-Output). The results showed that lagoons eliminated the quasi-totality of organic matters (about 80% of BOD) and dissolved substances (about 50 to 90%). Nevertheless, a decrease of epuration efficiency that has been observed in winter of all elements (temperature, electric conductivity, pH, dissolved oxygen, redox potential, chloride, iron, manganese, nickel, zink, total nitrogen, total phosphorus, ammonia, BOD, COD), was due to the decrease of pH (pH=4,5). However, in the begining of summer only Cu2+ and Fe2+ decreased. The collapse of BOD removel (- 8% observed in September 1998) was linked to the excedentary stock of organic matter products in the basins during the summer. The analysis of the monthly evolution of the efficiency epuration of NH4+, total nitrogen (TN) and total phosphorus (TP) indicate similary features. The net budget fluctuates between 50% in winter and 70% in summer. The weak values are noted in January 1999 (19% for NH4+ , 13% for TN and 14% for TP). This work showed that the natural lagooning is weakly efficient for this kind of landfill leachates