Sulla modellazione meccanica di giunzioni adesive tra elementi tubolari di materiale composito fibrorinforzato

2016 - 2017Traditional materials (steel, concrete, timber and masonry) still dominate the building industry. However new materials are constantly being explored by engineers and scientists due to their numerous advantages offered. With the acronym FRP (Fibre Reinforced Polymers) we indicate a family of composite materials obtained by coupling a polymeric matrix and fibres. More specifically, high strength fibres (glass, carbon, aramid or ultra-thin steel wires) provide strength and stiffness while the resin (polyester, vinylester or epoxy) protects the fibres and guarantees the stress transfer between them. As a result, enhanced final properties are obtained with respect to those exhibited by the individual constituents. Nowadays composite materials are widely used for the strengthening and repair of civil structures. This is due to their advantages such as light-weight, good mechanical properties and corrosion-resistance. Composite materials are also appropriate for applications where the aesthetic preservation of the original structure is required (buildings of historic or artistic interest) or where traditional strengthening techniques cannot be effectively employed. Composite materials are available in several geometries types ranging from laminates with regular surfaces to bi-directional fabrics that are easily adaptable to the shape of the member being strengthened. The evolution and the study of these materials has also encouraged their use not only as structural reinforcements, but also as main structural elements made of pultruded profiles... [edited by Author]XXX cicl

Preliminary Assessment of Radiolysis for the Cooling Water System in the Rotating Target of {SORGENTINA}-{RF}

The SORGENTINA-RF project aims at developing a 14 MeV fusion neutron source featuring an emission rate in the order of 5-7 x 10(13) s(-1). The plant relies on a metallic water-cooled rotating target and a deuterium (50%) and tritium (50%) ion beam. Beyond the main focus of medical radioisotope production, the source may represent a multi-purpose neutron facility by implementing a series of neutron-based techniques. Among the different engineering and technological issues to be addressed, the production of incondensable gases and corrosion product into the rotating target deserves a dedicated investigation. In this study, a preliminary analysis is carried out, considering the general layout of the target and the present choice of the target material

Cohesive interface behaviour and local shear strains in axially loaded composite annular tubes

The local behaviour of a composite profile with annular cross-section is studied in presence of interfacial cohesive forces at the ends, where the lateral surface may be involved in a bonding connection. Features include the possibility of warping displacements, nonlinear shear strains within the thickness of the annular wall originated by the bonding interactions. Numerical simulations are carried out in order to investigate the tube behaviour over the loading path up to the failure, thus underlining the relevance of the thickness on the magnitude of the shear strain

An Experimental/Numerical Study on the Interfacial Damage of Bonded Joints for Fibre-Reinforced Polymer Profiles at Service Conditions

International audienceIn this paper a study on double lap joints made of glass fibre-reinforced polymer (GFRP)adherents and an epoxy resin as a glue is performed. Both an experimental procedure and a theoreticalmodel with an associated numerical discretization are presented. Experimental and numerical resultsare discussed and compared. They indicate the possibility of performing an advanced mechanicalanalysis of adhesive joints based on a preliminary characterization of a few mechanical parameters

Residual stiffness of bonded joints for fibre-reinforced polymer profiles

In this paper we present an experimental study on the behaviour of samples concerning double lap joints made of glass fibre-reinforced polymer composite (GFRP). According to a multistep displacement/force control procedure, a data driven approach is performed with the aim of investigating the behaviuor of adhesive joints between GFRP profiles at service conditions focusing on the non-linearity of the interfacial damage as the number of cycles increases. The present analysis has been performed regardless of the consideration of material/geometric non-linearities, which affect, instead, the failure load or the buckling limit. The final results provide a database for sketching a predictive rule to be used for a direct evaluation of the loss of stiffness of the joint

SORGENTINA-RF project: fusion neutrons for 99Mo medical radioisotope

International audienc

Preliminary Assessment of Radiolysis for the Cooling Water System in the Rotating Target of SORGENTINA-RF

The SORGENTINA-RF project aims at developing a 14 MeV fusion neutron source featuring an emission rate in the order of 5–7 × 1013 s−1. The plant relies on a metallic water-cooled rotating target and a deuterium (50%) and tritium (50%) ion beam. Beyond the main focus of medical radioisotope production, the source may represent a multi-purpose neutron facility by implementing a series of neutron-based techniques. Among the different engineering and technological issues to be addressed, the production of incondensable gases and corrosion product into the rotating target deserves a dedicated investigation. In this study, a preliminary analysis is carried out, considering the general layout of the target and the present choice of the target material