Search results for " progettazione."
showing 10 items of 503 documents
STUDIO FLUIDODINAMICO DI OTTIMIZZAZIONE DI FORMA IN CAMPO AUTOMOBILISTICO E NAVALE, CON IMPLEMENTAZIONE DEI CODICI CFD NEI SOFTWARE VPP
2011
AN IN-VITRO PHANTOM STUDY ON THE THORACIC AORTIC STENT GRAFT COLLAPSE RESULTING FROM A BIRD-BEAK CONFIGURATION INTO THE AORTIC ARCH
2014
Analysis of the Behaviour of an Optimized Magnetorheological Brake
2013
This paper presents the optimization process of MR – magnetorheological brake in order to define its configuration, and to reach the requested vehicle braking torque. FEM analysis previously carried out, concerning structural sizing of such a brake, showed that both braking torque and brake mass did not satisfy the requirements. Due to the necessity of limitation on the suspended mass of a motor vehicle, the optimization of the form of MR brake stator has been executed, including determination of its contribution to the total mass of the brake. Thus a percentage reduction of approximately 40% was obtained. In order to estimate the brake temperature which results from the transformation into…
Effect of residual stresses and their redistribution on the fatigue crack growth in cold-worked holes
2009
The cold-expansion process is widely used to enhance the fatigue life of structures with fastener holes. Various studies assert that the cold-expansion improves the fatigue strength of fastener holes; however, the improvement of fatigue life is difficult to quantify. The influence on fatigue life of cold-worked hole in a 6061-T6 alluminum allosy was studied by numerical and experimental tests. Fatigue crack growth tests were carried out to find the crack length and growth rates of crack propagating from hole edge. Thus, the cold-expansion process was modeled with a Lagrangian implicit code for metal forming to obtain the residual stress field. Progressive crack growth along the observed fat…
ELEMENTO D’INTERFACCIA PER LA SIMULAZIONE DI PROCESSI DI DANNEGGIAMENTO IN MODO MISTO I/II NEI MATERIALI COMPOSITI E NELLE GIUNZIONI ADESIVE
2018
E’ stato sviluppato un elemento coesivo in grado di connettere e simulare la crescita delle cricche tra sottodomini di elementi finiti modellati in modo indipendente con mesh incompatibili. L'approccio si basa su funzioni di penalità e presenta numerosi vantaggi rispetto alle tecniche FEM convenzionali nelle simulazioni di delaminazione. Il più importante è la possibilità di rilasciare una porzione dell'interfaccia più piccola della lunghezza degli elementi finiti locali. Pertanto la delaminazione non avanza solamente rilasciando i nodi del modello FEM, una limitazione comune a molti metodi trovati in letteratura. È stato anche sviluppato un nuovo approccio per modellare la crescita delle c…
A penalty-based interface technology
2009
Modern computers have enabled engineers to perform large scale analyses of complex structures like entire aircrafts, automobiles, and ships. One issue that arises often is the need to perform a unified analysis of a structural assembly using sub-structural models created independently. These sub-structural models are frequently designed by different engineers, thus they are likely to be incompatible at their interfaces. Finite element interface technology has been developed to facilitate the joining of independently modeled substructures. Here an effective and robust interface element is presented. This method has been developed using penalty constraints and allows computationally efficient…
Predicting Outcome of Type B Aortic Dissection with Patent False Lumen by Computational Flow Analysis
2014
Ottimizzazione di un freno a fluido magnetoreologico per uso automobilistico
2009
Il presente lavoro ha come oggetto lo studio numerico di un freno a fluido magnetoreologico (MR) per uso automobilistico tramite il codice agli elementi finiti ANSYS. In seguito ad un dimensionamento analitico preliminare del freno la realizzazione di un modello FEM magnetico permette un’accurata valutazione della distribuzione del campo magnetico nel fluido MR e la valutazione del momento frenante generato in seguito all’applicazione della corrente alla bobina. La successiva ottimizzazione in due fasi del circuito magnetico consente di migliorarne le prestazioni in termini di momento frenante e peso del dispositivo. L’analisi FEM termica di tipo dinamico permette infine di valutare l’andam…
DESIGN AND OPTIMIZATION OF A CHASSIS FOR A FORMULA SAE RACE CAR
2009
In this paper, the design process of a new chassis for a Formula SAE car is presented. The chassis is undoubtedly one of the most important parts of the car, both for the influence that it has on the vehicle dynamic behaviour, and because it is the main component that assures the driver safety. The new designed chassis is composed of many structural tubular bars and has been equipped with systems for the joining of all the auxiliary members. After the definition of the masses distribution and the choice of the main dimensions, preliminary CAD and FEM models have been carried out for the evaluation of the structural behaviour of this kind of vehicle. Successively, in order maximizing the tor…
Influence on the Dynamic Behavior of Full Car Equipped by Magnetorheological Damper via Switch on/off and h∞ Controller
2011
This paper shows the influence on dynamic behavior of the car when it is equipped with magneto-rheological dampers controlled by a feedback. The feedback is built up in two ways; the first is implemented by a switch on/off control that is characterized by the injection of magnetic field with a constant value. It happens when a certain value of relative speed between the sprung and unsprung mass is exceeded. The second feedback is characterized by the H-infinity control which is based on the relative displacement in order to vary the magnetic field signal in a continuous manner. At the same time the H-infinity control of vehicle is maintained by taking into account the exceeding of speed sig…