Search results for " Cost"

BEM analysis of a piezoelectric structural health monitoring system for delamination detection

2013

In the present work a piezoelectric based structural health monitoring (SHM) system is analyzed with the aim of assessing the ability of the piezoelectric patch to detect both edge and embedded delaminations proper of flange-skin composite laminated structures. he boundary element model is developed for piezoelectric solids and is implemented by taking advantage of the multidomain technique to model laminated and cracked configurations. A non-linear spring model interface is then implemented in conjunction with an iterative procedure allowing for the simulation of the finite stiffness of the bonding layers as well as of the non-penetration condition of the delamination surfaces. he dynamic …

On the use of the EMI for the health monitoring of bonded elements

2014

The low weight, robustness and fatigue resistance of adhesive joints make them suitable for structural joints. A fully developed nondestructive evaluation technique however is needed to monitor and assess the quality of bonded joints. In the present paper the application of the electromechanical impedance (EMI) technique is proposed. In the EMI method a piezoelectric transducer (PZT) is attached to the structure of interest. The high sensitivity and low power consumption make the EMI method feasible for real time structural health monitoring. In this study we investigated the sensitivity of the electromechanical response of a PZT to the curing and the quality of the adhesive used for bonded…

Socially-aware Dynamic Computation Offloading Scheme for Fog Computing System with Energy Harvesting Devices

2018

Fog computing is considered as a promising technology to meet the ever-increasing computation requests from a wide variety of mobile applications. By offloading the computation-intensive requests to the fog node or the central cloud, the performance of the applications, such as energy consumption and delay, are able to be significantly enhanced. Meanwhile, utilizing the recent advances of social network and energy harvesting (EH) techniques, the system performance could be further improved. In this paper, we take the social relationships of the EH mobile devices (MDs) into the design of computational offloading scheme in fog computing. With the objective to minimize the social group executi…

VELENI ED ALCHIMIE NEI MATERIALI DELL’EDILIZIA PRE INDUSTRIALE

2019

Since at least two decades, a renewed sensitivity to biocompatibility and the consequent diffusion of eco-certified building products have led to the attention of designers and operators on the issue of the healthness of construction materials. Although the application of strict protocols guarantees for new constructions very high levels of healthiness for both construction workers and users who come into direct contact with building materials and components, the issue for the characterization of potentially hazardous materials arises in many case for historical buildings. In addition to the well-known asbestos problem, there are new worrying signs deriving from the ascertainment in the inc…

Shear and flexural strength of corroded R.C. beams

2016

Simplified equations aimed at evaluating the flexural and shear capacity of corroded R.C. beams are presented and discussed in this paper, with reference to ordinary beams reinforced both longitudinally (with same-size bars) and transversely (with stirrups). A model is developed to take care of diffused and localised corrosion (pitting corrosion), concrete decay in compression and bond-strength decay at concrete-reinforcement interface. A fairly innovative contribution of this study is the introduction into the proposed equations of the main parameters governing the corrosion processes. The proposed approach is simple and effective, and may be adopted in the assessment of many damaged struc…

Les plafonds voûtés des traités historiques aux applications en Sicile

2016

I controsoffitti lignei voltati - a partire dal XVII secolo e con notevole diffusione ed impiego nel XVIII secolo in tutta l’Europa - hanno qualificato sia edifici pubblici e privati di pregio che anche gran parte dell’edilizia di base, per le loro caratteristiche di indipendenza strutturale, leggerezza e di facile assemblaggio delle parti. Lo studio e la ricerca vogliono restituire memoria dei materiali costitutivi e delle tecniche costruttive impiegate nella realizzazione dei manufatti, per offrire un utile strumento di conoscenza agli studiosi ed ai tanti operatori del settore impegnati nell’intervento di recupero e/o restauro. C’est grâce à l’indépendance structurelle, à la légèreté et …

Interaction problems between in-plane and out-plane plates by SBEM

2010

Drainage inlets efficiency and its impact on pluvial flooding hazard evaluation uncertainty

2014

Flooding events in urban areas occur quite frequently as a consequence of rain events of lower intensity than the design one, even in case of correct network dimensioning. Inlets are in those cases the critical nodes, and efficient drainage is only ensured when care is taken on their appropriate design and positioning within the pluvial flood-prone areas. Classical approach for design and position of these hydraulic structures can result in high level of uncertainty in defining properly risk levels in urban areas. Further, evaluation of flood hazard in urban areas is made even more difficult if one considers that pluvial flooding can be caused by storm events characterised by a low return t…

Analysis of FBG reflection spectra under uniform and non-uniform transverse loads

2019

Loads applied transversely on the external surface of waveguides change their circular cross-sectional geometry generating birefringence. Due to this effect the reflected spectrum of a Fibre Bragg grating (FBG) undergoes a splitting of the single peak of the Bragg wavelength. In this work, we employed the Transfer Matrix Method (TMM) for x- and y-polarized wave-modes to model the uniform FBG reflection spectra for uniform and non-uniform transverse loads. We also performed experimental measurements for two different transverse load scenarios. The load profiles chosen for these experiments were applied on the FBG sensor through a block of steel and a roll bearing pin. Then, the modelled and …

A Cohesive-frictional Grain-boundary Technique for Microstructural Analysis of Polycrystalline Materials

2018

The development of a 3D microstructural model for the analysis of degradation and failure in polycrystalline materials is reviewed in the present chapter. The material is explicitly modelled at the grain level, using integral equations in conjunction with a phenomenological crystal plasticity framework for the bulk grains, and with cohesive-frictional laws to represent inter-granular micro-cracking processes. The method allows to capture the initiation, development and coalescence of damage or plasticity at the aggregate scale. The formulation’s key feature is the representation of the mechanical problem in terms of inter-granular variables only, which allows to reduce the computational cos…