This article considers the sandwich structures with aluminium (Al) foams of various thicknesses in conjunction with skins composed of fibre-metal laminates (FML). The FMLs with Al sheet and glass fiber reinforced polypropylene (GFPP) composites were integrated with Al foam for composing the sandwich panels. The FML-foam sandwich systems were manufactured by hot pressing in a mold at 200 C under 1.5 MPa pressure. The bonding between the components of the sandwich was achieved by various surface modification techniques, i.e., silane surface treatment, PP adhesive film additition, and their combination. The Al sheet/Al foam sandwiches were also prepared by bonding the components with an epoxy adhesive for comparing the effect of GFPP on the mechanical performance of the sandwich structures. The energy absorption capacities together with compressive mechanical behavior of both Al foams and FML-foam sandwich systems were evaluated by flatwise compression tests. Experiments were performed on samples of varying foam thicknesses.

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Application of blast tests causes some problems to characterize the performance of panels due to the drastic conditions of explosive medium. Real test has high safety concerns and is not easily accessible because of its extra budget. Some approaches are needed for the preliminary predictions of dynamic characteristics of panels under blast loading conditions. In this study, the response of sandwiches under blast effect was evaluated by combining quasi-static experiments and computational blast test data. The primary aim is to relate the quasi-static panel analysis to dynamic blast load. Based on this idea, lightweight sandwich composites were subjected to quasi-static compression loading with a special test apparatus and the samples were assumed as single degree-of-freedom mass-spring systems to include dynamic effect. This approach provides a simpler way to simulate the blast loading over the surface of the panels and reveals the possible failure mechanisms without applying any explosives. Therefore the design of the panels can be revised by considering quasi-static test results. In this work, the peak deflections and survivabilities of sandwiches for various explosive weights were predicted based on the formulations reported in the literature. Major failure types were also identified and evaluated with respect to their thicknesses.

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A number of nanoclay/poly(methyl methacrylate) (PMMA) composite films were prepared with three different clay concentrations (0.5 %, 1 % and 2 % (w/%)) via a solution-casting process. The nanoclay was modified by applying different compatibilization techniques: mere silane surface treatment and surfactant application with the addition of a silane agent. The interlayer distances of the clay galleries were determined using X-ray diffraction (XRD) and the modifications were verified with Fourier-transform infrared spectroscopy (FTIR) analysis. The dynamic mechanical analyses (DMA) were performed to clarify the viscoelastic properties of the produced films. Morphological characterizations were carried out with a scanning electron microscope (SEM). The neat clay/PMMA composites and pure PMMA film were also used to compare the effects of the compatibilization methods. The silane-modified clay/PMMA composites exhibited the best performance, as compared to neat PMMA, by considering the storage modulus (17.7 % increase) and the glass-transition temperature (20 % increase). However, in terms of the dynamic mechanical properties, the joint implementation of these two modification techniques did not satisfy the expectations, probably due to the excess modifier and the plasticizing effect.Avtorji so s tako imenovanim raztopno-ulivnim procesom pripravili {tevilne kompozitne filme (tanke prevleke) na osnovi nanogline/polimetil metakrilata (PMMA) s tremi razli~nimi koncentracijami gline (0,5, 1 in 2 masnih dele`ev). Nanoglino so modificirali z razli~nimi kompatibilizacijskimi tehnikami: s povr{insko obdelavo s silanom (SiH4) ter z aplikacijo povr{insko aktivne snovi z dodatkom za tvorbo silana. Razdalje med galerijami plasti gline so dolo~ili z rentgensko difrakcijo (XRD) in modifikacije so verificirali z infrarde~o spektroskopijo s Fourierjevo transformacijo (FTIR). Dinami~ne mehanske analize (DMA) so izvedli, da bi razjasnili viskoelasti~ne lastnosti izdelanih filmov. Morfolo{ke lastnosti filmov pa so okarakterizirali z vrsti~nim elektronskim mikroskopom (SEM). Med seboj so primerjali izdelane kompozite glina/PMMA in~isti PMMA ter s tem ugotavljali u~inkovitost kompatibilizacijskih metod. S silanom modificirani kompoziti glina/PMMA ka`ejo bolj{e lastnosti v primerjavi s~istim PMMA; meritev modula shranjene energije je pokazala 17,7 % izbolj{anje in temperatura prehoda v steklasto stanje se je povi{ala za 20 %. Vendar pa implementacija obeh tehnik modifikacije z vidika dinami~nih lastnosti ni izpolnila pri~akovanj, verjetno zaradi prebitka modifikatorja in u~inka plastificiranja.