Search results for "PROGETTAZIONE"
showing 10 items of 581 documents
Design of a telescopic tower for wind energy production with reduced environmental impact
2019
A prototype of a telescopic pole for wind energy production with low environmental impact and its lifting system for a 60 to 250 kW turbine and a height of 30 m have been designed and manufactured. A telescopic tower, which is raised and lowered by automation or by remote control, allows to differentiate the presence of the generator within the landscape over time. The technology currently available for lifting and lowering wind turbines is made up of telescopic poles of heights of less than 10 meters and with tilting posts of height below 30 m. Without a state of the art to refer to, the telescopic pole and its lifting system have been designed starting from scratch and solving with innova…
A flexible robotic cell for in-process inspection of multi-pass welds
2020
Welds are currently only inspected after all the passes are complete and after allowing sufficient time for any hydrogen cracking to develop, typically over several days. Any defects introduced between passes are therefore unreported until fully buried, greatly complicating rework and also delaying early corrections to the weld process parameters. In-process inspection can provide early intervention but involves many challenges, including operation at high temperatures with significant gradients affecting acoustic velocities and, hence, beam directions. Reflections from the incomplete parts of the weld would also be flagged as lack-of-fusion defects, requiring the region of interest (ROI) t…
Evaluation of Coded Excitations for Autonomous Airborne Ultrasonic Inspection
2019
Unmanned Aerial Vehicles (UAVs) are receiving increasing attention for use in Non-Destructive Testing due to their ability to access areas where manual inspection is not practical. Contact-based UAV ultrasonic inspections grant the opportunity to remotely monitor the structural health of an industrial asset with enhanced internal integrity information. Ultrasonic inspection is a Non-Destructive Testing (NDT) method conventionally used in corrosion mapping. Surface contacting ultrasonic transducers provide enhanced structural integrity information. However, due to near-surface aerodynamic effects, angular sensitivity of the ultrasound probe and alignment error during autonomous inspections, …
Cohesive Model for the Simulation of Crack Initiation and Propagation in Mixed-Mode I/II in Composite Materials
2019
A cohesive element able to connect and simulate crack growth between independently modeled finite element subdomains with non-matching meshes is proposed and validated. The approach is based on penalty constraints and has several advantages over conventional FE techniques in disconnecting two regions of a model during crack growth. The most important is the ability to release portion of the interface that are smaller than the local finite element length. Thus, the growth of delamination is not limited to advancing by releasing nodes of the FE model, which is a limitation common to the methods found in the literature. Furthermore, it is possible to vary the penalty parameter within the cohes…
SAFETY CONSIDERATIONS ON TEENAGE PEDESTRIAN-BUS IMPACT
2019
This work studies the impact conditions between the adolescent pedestrian and the bus focusing on head and chest injury. The injury to the head is analyzed using both the Head Injury Criterion (HIC) 36 and the HIC15 parameters as established by the most advanced legislation and comparing the risk probability Abbreviated Injury Scale (AIS3+) and AIS4+. The parameter HIC15 gives a higher probability of risk with lower values, and therefore it can be considered more conservative. Moreover, the study of chest injury is performed with two different biomechanical parameters: the Thoracic Trauma Index (TTI) and the TTI(d); the last neglects the pedestrian mass. The results indicate that the param…
Absorption kinetics and swelling stresses in hydrothermally aged epoxies investigated by photoelastic image analysis
2015
Abstract The present work proposes an experimental optical methodology able to measure the transient swelling stresses induced by the water uptake ageing of polymers. In particular, the work describes the implementation of a Photoelastic technique to quantify internal stresses arising during the hydrothermal ageing of cast epoxy samples. The material investigated is a model DGEBA/DDS epoxy system. Curing and post-curing cycles have been optimised in order to obtain a fully cured, high T g , and completely stress free initial condition. Rectangular beam samples were then left in a hydrothermal bath at 90 °C, and regularly monitored by gravimetric and photoelastic analyses. The quantitative e…
Numerical simulations demonstrate that the double tapering of the spatualae of lizards and insects maximize both detachment resistance and stability
2011
Many biological attachment devices of insects, spiders and geckos consist of arrays of hairs (setae), which are terminated by contact elements of different shapes. However, the most frequently observed shape is a thin plate-like spatula. In spite of a rather wide range of sizes, most spatulae of different animals are not uniform, but rather possess a gradient in thickness and width. Here we show that the spatulae of insects and geckos become gradually thinner and wider approaching the end. This geometrical effect is explained in the present paper, by using a numerical approach for the modelling of the van der Waals adhesion and friction between the contact elements and the substrate. The ap…
Mechanics of pericardial effusion: A simulation study
2015
Pericardial effusion is a pathological accumulation of fluid within pericardial cavity, which may compress heart chambers with hemodynamic impairment. We sought to determine the mechanics underlying the physiology of the hemodynamic impairment due to pericardial effusion using patient-specific computational modeling. Computational models of left ventricle and right ventricle were based on magnetic resonance images obtained from patients with pericardial effusion and controls. Myocardial material parameters were adjusted, so that volumes of ventricular chambers and pericardial effusion agreed with magnetic resonance imaging data. End-diastolic and end-systolic pressure–volume relationships …
Introduzione
2014
L’opera di Vincenza Garofalo, “Unbuilt. Quattro progetti di Alberto Sartoris", assume la forma di una ricerca fondata su un dispositivo metodologico e culturale ampio che penetra in profondità nei territori dell’analisi filologica, dell’estetica, della critica architettonica e, naturalmente, della “Scienza della Rappresentazione”. Il campo di indagine è quello degli esiti di una sperimentazione progettuale che non si traduce in concreta forma fisica, per mezzo dell’atto del costruire, e che per questo necessita di pratiche esperenziali estese che implicano maggiori livelli di approfondimento critico-relazionali e specificità disciplinari in grado di fare avanzare la “percezione” in direzion…
Influence of Joint Geometry on Micro and Macro Mechanical Properties of Friction Stir Spot Welded Joints
2014
AbstractSpot welding can be considered a very common joining technique in automotive and transportation industries as it permits to obtain effective lap-joints with short process times and what is more it is easily developed through robots and automated systems. Recently, Friction Stir Spot Welding (FSSW) has been proposed as a natural evolution of the already known Friction Stir Welding (FSW) process, allowing to obtain sound spot joints that do not suffer from the insurgence of typical welding defects due to the melting of the base material. Similarly to FSW, both geometrical and technological parameters must be considered as they affect the material flow and the heat flux generated durin…