Search results for " meccanica"

Testing the Dispersion of Nanoparticles in a Nanocomposite with an Ultra-Low Fill Content Using a Novel Non-Destructive Evaluation Technique

2022

A non-destructive evaluation (NDE) technique capable of testing the dispersion of nanoparticles in a nanocomposite would be of great use to the industry to check the quality of the products made and to ensure compliance with their specifications. Very few NDE techniques found in the literature can evaluate the level of dispersion of the nanoparticles in the whole nanocomposite. Here, a recently developed NDE technique based on pulsed phase thermography (PPT) in transmission mode was used to assess the particle dispersion in ultra-low, less than 0.05 wt%, Ag enriched polymeric based nanocomposite manufactured with an innovative nano-coating fragmentation technique. The phasegrams obtained wi…

Hybrid nanocomposites with ultra-low filling content by nano-coating fragmentation

2021

In the current study, a new technique for the manufacturing of polymer nanocomposites (PNCs) with ultra-low filling content (<0.05 wt%) is presented. Specifically, this method has been validated through the production of polypropylene (PP) nanocomposites with Ag nanoparticles. The presented method first consisted in a metal nano-film deposition on PP pellet substrates by a physical vapor deposition (PVD) sputtering equipment. Subsequently, a percentage of the coated pellet was mixed to uncoated ones via an injection molding machine to produce the PNC in a single step. Different mixing percentages of coated PP pellet to the uncoated ones were studied. As a result, the fragmentation of the…

Micromechanical Modeling of Aortic Pathologies

2021

Analysis and optimization of hybrid double lap aluminum-GFRP joints

2014

In this paper a systematic investigation of the mechanical performance of hybrid double-lap Al-GFRP bonded-bolted joints, has been carried out by using experimental analyses and numerical simulations. In order to detect the optimal geometric configuration, as well as to highlight the contribution of adhesive and bolts, the results relative to hybrid joints have been compared with those of simply adhesively bonded and simply bolted joints. The experimental and numerical results have shown that by using the minimum overlap length provided from theory, the bolt leads to a significant decreasing of both the maximum shear and the maximum peel stresses in the adhesive layer and, consequently, the…

Numerical experimental analysis of hybrid double lap aluminum-CFRP joints

2015

Abstract Due to their reliability and ease of assembly, both the adhesively bonded and the mechanical joints are commonly used in different fields of modern industrial design and manufacturing, to joint composite materials or composites with metals. As it is well known, adhesively bonded joints are characterized by high stiffness and good fatigue life, although delamination phenomena localized near the free edges may limit their use, especially for applications where corrosive environments and/or moisture can lead to premature failure of the bonding. In these cases, a possible alternative is given by the well-known mechanical joints. On the contrary, these last joints (bolted, riveted) requ…

Stiffness and Reinforcement Effect of electrical Resistance Strain Gauges

2007

:  The increasing use of low-modulus materials, on which the reinforcement effect of the electrical resistance strain gauge is not negligible, has re-opened the research interest into this issue. This study deals with the evaluation of stiffness, and of the strain gauge Young's modulus involved in the estimation of both the global and the local reinforcement effect; the relationship between the strain gauge stiffness and the local reinforcement effect is also analysed. In particular, the experimental technique used to determine the stiffness of some commercial strain gauges is described. The results show that the strain gauge stiffness alone does not permit an accurate evaluation of the loc…

Mechanical Performance of CNT Fibres

2014

The initial strength hype over carbon nanotubes arose from predictions of the strength of individual graphene layers, encouraged by measurements of individual MWCNTs and SWCNT bundles in AFM. The challenge for fibres composed of carbon nanotubes (CNTs) is to translate the impressive properties of the individual carbon nanotubes into the fibres. Yarn-like fibres composed of carbon nanotubes made by the direct spinning process have been used as the subject of this study. There have been occasional observations of strengths greater than 5 N/tex, which have served to maintain the enthusiasm for on-going developments. Here, we will re-examine those reports in the context of the response of nanot…

STUDIO DELLE PROPRIETÀ MECCANICHE ED ELETTROMECCANICHE DI NANOCOMPOSITI E NANOFIBRE MEDIANTE APPROCCI NUMERICI

Novel non-destructive inspection techniques for laser powder deposition inspection

2013

A novel non-destructive testing (NDT) techniques for inspection of parts and components manufactured by Additive Manufacturing Processes (AMP), in particular Laser Metal Deposition (LMD), has been developed. LMD is a technology that has been maturing over the last 20 years and has found application in repair, coatings, hybrid build and 3D near net shape manufacture of small intricate parts that can be used in aero and automobile engines to improve efficiency. Currently this technology cannot be used to supply some of these parts because absence of flaws, which might be left in the component during manufacture, cannot be guaranteed. Today, quality is assessed by sample destructive testing, w…

NuGO: i nuovi orizzonti della ricerca internazionale in nutrigenomica

2014

Convegno sulla ricerca nella nutrigenomica