Search results for " COSTRUZIONE"

Giacomo Amato: composizione e costruzione dell'architettura siciliana tra Seicento e Settecento

2017

Il contributo analizza la carriera dell'architetto palermitano Giacomo Amato alla luce delle sue competenze tecnico-costruttive. Il temi indagati in quest'occasione - progettazione e costruzione di scale, i materiali per l'architettura, interventi di consolidamento strutturale e perizie dopo il terremoto del 1726 (cupole e Steri) - delineano una figura professionale poliedrica nella Sicilia del Sei-Settecento

Mechanical properties of carbon nanotube fibres: St Venant’s principle at the limit and the role of imperfections

2015

Abstract Carbon nanotube (CNT) fibres, especially if perfect in terms of their purity and alignment, are extremely anisotropic. With their high axial strength but ready slippage between the CNTs, there is utmost difficulty in transferring uniformly any applied force. Finite element analysis is used to predict the stress distribution in CNT fibres loaded by grips attached to their surface, along with the resulting tensile stress–strain curves. This study demonstrates that, in accordance with St Venant’s principle, very considerable length-to-diameter ratios (∼103) are required before the stress becomes uniform across the fibre, even at low strains. It is proposed that lack of perfect orienta…

Thermoelastic stress analysis of a 2D stress field using a single detector infrared scanner and lock-in filtering

2009

A low resolution, low cost, fast infrared scanner is used to acquire the temperature change along a line on the surface of cyclically loaded samples. The temperature signal is sampled versus time by exploiting the raster scanning movement of the thermocamera single detector. The temperature data is then post-processed by a Fast Fourier Transform based lock- in algorithm implemented in MATLAB ® , in order to filter out the thermoelastic effect induced temperature change. A procedure is also implemented in order to extend the data sampling time by opportunely synchronising successively grabbed data frames. The effectiveness of such synchronisation procedure is first demonstrated by performing…

A New Procedure for the Evaluation of Non-Uniform Residual Stresses by the Hole Drilling Method Based on the Newton-Raphson Technique

2010

The hole drilling method is one of the most used semi-destructive techniques for the analysis of residual stresses in mechanical components. The non-uniform stresses are evaluated by solving an integral equation in which the strains relieved by drilling a hole are introduced. In this paper a new calculation procedure, based on the Newton-Raphson method for the determination of zeroes of functions, is presented. This technique allows the user to introduce complex and effective forms of stress functions for the solution of the problem. All the relationships needed for the evaluation of the stresses are obtained in explicit form, eliminating the need to use additional mathematical tools. The t…

Defect detection in additively manufactured titanium prosthesis by flying laser scanning thermography

2018

Abstract Metal additive manufacturing is nowadays a well-established technology for cutting edge applications in the automotive, aerospace, defense and medical sectors. Since additive metal deposition is basically a welding method, which creates parts by successively adding layers of material, there is a chance for defects like pores, cracks, inclusions and lack of fusion to develop. As a matter of fact, interlayer and intralayer defects are often observed in additive manufactured components. However, if one considers the typical end applications along with the high costs involved in metal additive manufactured components, a “zero defect” target is close to mandatory for this technology. Pl…

Flying laser spot thermography for the inspection of aerospace grade Fibre Metal Laminates

2017

This work analyses a Non Destructive Testing approach for the detection of interlayer disbonds in aerospace grade Fibre Metal Laminates (FMLs). The NDT setup consists of a continuous laser, focused and moved over the material surface, while an IR thermal camera acquires its thermal footprint. A numerical model of the NDT setup is presented, where the material thermal response is analysed to evaluate the features of the defects signatures. In particular, the response from various types of FMLs is evaluated.

Carbon Nanotubes Dispersion Assessment in Nanocomposites by Means of a Pulsed Thermographic Approach

2020

The extensive production of polymer composites reinforced by carbon nanotube is limited by the absence of non-destructive evaluation (NDE) methods capable of assessing product quality to guarantee compliance with specifications. It is well known that the level of dispersion of carbon nanotubes (CNTs) in the polymer matrix is the parameter that, much more than others, can influence their enhancement capabilities. Here an active Infrared Thermography Non Destructive Testing(IR-NDT) inspection, joined with pulsed phase thermography (PPT), were applied for the first time to epoxy-CNT composites to evaluate the level of dispersion of the nanoparticles. The PPT approach was tested on three groups…

L’Item Response Theory nella costruzione degli strumenti psicometrici.

2008

IL COMFORT INDOOR, STRUMENTI LEGISLATIVI: PANORAMA LEGISLATIVO INTERNAZIONALE E NAZIONALE

2022

Già da qualche decennio si parla di IEQ (Indoor Environmental Quality) con particolare attenzione sulla salubrità dell’ambiente costruito e alla sua possibile influenza sulla sostenibilità ambientale. Tale interesse si è riversato per lo più sulla qualità dei prodotti e delle tecnologie dell’edilizia, incentrando la questione sulle prestazioni di essi e sugli effetti ambientali che essi generano. Con gli obiettivi previsti dall’Agenda 2030 si supera l’idea che la sostenibilità sia una prerogativa ambientale e si afferma una visione olistica mirata alla salute umana (obiettivo 3), emergendo la necessità di un passaggio da un approccio “Green” al costruito verso un approccio “Human Centred” c…

Enabling robotic adaptive behaviour capabilities for new industry 4.0 automated quality inspection paradigms

2020

The seamless integration of industrial robotic arms with server computers, sensors and actuators can revolutionise the way in which automated non-destructive testing (NDT) is performed and conceived. Achieving effective integration and realising the full potential of robotic systems presents significant challenges, since robots, sensors and end-effector tools are often not necessarily designed to be put together and form a holistic system. This paper presents recent breakthroughs, opening up new scenarios for the inspection of product quality in advanced manufacturing. Many years of research have brought to software platforms the ability to integrate external data acquisition instrumentatio…