Search results for " Sandwich"
showing 10 items of 23 documents
Manufacture of marine composite sandwich structures
2016
Abstract The aim of this chapter is to present the main processes of manufacture of composite sandwich structures used in marine applications. In the introduction, sandwich structure classification and properties and advantages/disadvantages in their uses are presented. In the second and third section, the main used technologies to made sandwich are, respectively, described and compared. Then, the goodness of these techniques is evidenced with the discussion of some experimental results obtained by the authors in their studies. The last section concludes with a thorough list of the future trends.
EXPERIMENTAL AND NUMERICAL EVALUATION OF THE MECHANICAL BEHAVIOUR OF GFRP SANDWICH PANELS
2007
This work deals with the analysis of the mechanical behaviour of a class of sandwich structures widely employed in marine constructions, constituted by fiber-glass laminate skins over PVC foam or polyester mat cores. In detail, a systematic experimental study and numerical simulations have shown that the theoretical prediction of the strength and the actual failure mechanism of these sandwich structures can be affected by significant errors, specially in the presence of prevalent shear loading. Moreover, because of the low shear stiffness and the elastic constants mismatch of the skins and core material, failure modes and strength are strongly influenced by eventual stresses orthogonal to t…
Indentation of rigidly supported sandwich beams with foam cores exhibiting non-linear compressive behaviour.
2011
A generalized analytical approach to investigate the indentation of sandwich beams under concentrated loads is presented, based on the Winkler foundation theory. A segment-wise model is implemented to the case of fully backed sandwich beams with polymeric foam cores exhibiting generic non-linear compressive behaviours. Closed-form analytical solutions of the indentation curve are obtained for simplified foam compression behaviours: elastic-perfectly-plastic, bilinear and bilinear-perfectly-plastic. Analytical predictions are compared with experimental data from sandwiches employing foam cores with peculiar non-linear behaviours. The proposed models are found to give a better match of the e…
The ALICE Transition Radiation Detector: Construction, operation, and performance
2018
The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/$c$ in p-Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction. The triggering capability is demonstrated both …
ANALISI DEL COMPORTAMENTO MECCANICO DI SANDWICH ECO-COMPATIBILI RINFORZATI CON FIBRE NATURALI
2015
The increasing environmental sensitivity in many industrial fields, from automotive to aeronautics to naval field, has led to an increasing demand of new bio-materials or renewable structural materials. In order to give a contribution to the design of eco-compatible structural materials, in this work new sandwich materials constituted by a core made by balsa and skins made by a composite material made by a “green” epoxy reinforced by agave fibers extracted from striated and americana agave obtained in Sicily by a proper research program financed by European founds. Previous theoretical analysis followed by systematical experimental analysis of the core, of the skins and the of the sandwich,…
Analysys and optimization of an end double-lap bonded joint for GFRP composite sandwich panels
2022
Although the best configuration of the joints used to connect a common GFRP sandwich panel with the main structures is the adhesively bonded one, that permit high static and fatigue performances as well as to avoid stress concentrations, mechanical or hybrid joints are still widely used in the industrial field. After a preliminary theoretical design, the optimal configuration of an end adhesively bonded double-lap joint constituted by a simple insert as internal adherent and the same face sheets as external adherent, has been researched. In detail, several experimental tests and successive numerical simulations under tensile and bending loading, performed by varying the main influence para…
A New Thermal Theory for Thermo-Mechanical Analysis of Composites
2009
The use of laminated and sandwich construction to achieve multi-functional objectives within a single structure continues to increase. It is especially desirable to use laminated construction in structures exposed to thermal loading, where heat resistant coating materials may be bonded to traditional structural materials. Design of such structures requires an accurate analysis of stresses induced by thermal as well as mechanical loads. A novel laminated plate theory and 3D finite element model based on first-order zig-zag sublaminate approximations are presented for thermal stress analysis of composite laminates and sandwich plates. The finite element is developed with the topology of an ei…
Investigation on the behaviour of fully thermoplastic composite sandwich beams under concentrated loads
2009
The recent development of new low cost manufacturing processes adopting thermoplastic matrices in the production of structural long fibre reinforced laminates is fostering an increasing interest towards this class of materials. The automotive sector in particular is attracted by the high energy absorbing, damage tolerance performances and manufacturing and recycling potentials of structural thermoplastic composites. In this study a number of fully thermoplastic sandwich beams have been manufactured in order to investigate flexural and shear rigidity performances as well as the indentation behavior under static concentrated loads.
OTTIMIZZAZIONE DI UNA GIUNZIONE INCOLLATA A DOPPIA SOVRAPPOSIZIONE PER SANDWICH IN COMPOSITO
2016
Grazie alle peculiari performances meccaniche, quali soprattutto l’elevata resistenza a flessione unita ad un basso peso specifico, le strutture sandwich in composito sono sempre più frequentemente utilizzate nella moderna progettazione industriale. Nel presente lavoro, considerando un composito sandwich con skins in vetroresina e core in PVC espanso, è stato eseguito uno studio numerico e sperimentale al fine di individuare la configurazione ottimale di una giunzione incollata a doppia sovrapposizione avente quali aderendi esterni le stesse skins del sandwich e aderendo interno costituito da un inserto in metallo o in composito. In dettaglio, previa preliminare ottimizzazione teorica della…