1,721,383 research outputs found
Optimization of process parameters and part geometry for high diameter tube hydroforming
No full textThe aim of this research is to study the feasibility of vases with tube hydroforming, identifying the limits of this technology. The goal of the simulation study was the identification of the maximum pressure needed to realize vases with big diameter and length. Initially the attention was focused on the realization of a square vase geometry. The initial tubes have a high diameter of 120 mm. Many simulations were conducted to optimize process parameters for this square geometry, namely actuators stroke and water pressure, but it wasn’t possible to completely achieve the die shape at the protrusion edges due to the big diameter expansion and to the rib geometries (thickness, height and fillet radii). Different vase geometries characterized by lower diameter expansion and same dimension of the ribs, were tested. The formability results were improved but there are still problems when the material is filling the ribs (material breakage). In order to realize a safe square part, it was necessary to optimize the rib geometrical dimensions. Other simulations were conducted for a round vase geometry, to check the maximum diameter expansion. Some general design rules were finally summarized
Pneumatic solution for multiple sample endoscope
No full textThe paper presents an innovative and original solution of a pneumatic micro forceps for multiple sample Gastro Intestinal (GI) endoscopy. The new device is based on the gastroenterologists requirements and wants to be a solution for shortening the operation time, for increasing the number and the quality of collected tissue samples by guaranteeing a good sample dimension and orientation, and for an overall cost reduction.
In fact, the use of biopsy tests to sample tissue and investigate the presence of diseases in human body is considerably increased in the last years.
The research is developed in close contact between medical doctors and engineers so to understand the GI endoscopy needs, identify new solutions, develop only feasible ideas and end up with a biopsy micro forceps prototype
Certificazione ISO 9001 e 14001
No full textMentre le informazioni relative alla ISO 9001 sono note da tempo, anche se meritano comunque di essere sempre richiamate, meno note sono quelle relative alla ISO 14001. Il presente articolo tratta delle problematiche connesse con l’implementazione di queste norme inerenti la qualità e l’ambiente sottolineando l’importanza della relativa certificazione
Development of an analytical model for the evaluation of friction coefficient in cold forming
No full textDevelopment and Implementation of an Algorithm for the Simulation of Material Welding in Extrusion Process
No full textExperimental and Simulative Applications of Incremental Forming with Full Die
No full textAmong the non conventional techniques to quickly obtain new prototypes, especially in the automotive field, Incremental Sheet Forming (ISF) represents an interesting alternative. TMS Research Group made several experiments and simulations on this topic with the aim of identifying and controling the most important process parameters.
The present paper, after a brief presentation of the developed ISF equipment and the first experiments, shows all the steps which led to the Full Die ISF process parameters optimization both for experiments and simulations. Thanks to the successful research strategy good agreement between simulative and experimental results was obtained
Influence of geometrical parameters on material welding in porthole die extrusion: FE analysis
No full textThe importance of aluminum extruded profiles is increasing more and more in many industrial fields. The most complex profiles presenting hollow section are cbtained using porthole die configurations. One of the most important phenomena taking place within this configuration is the material solid state welding that occurs when the flows reach the "welding chamber", located before the extrusion hole. The present paper describes the implementation of the welding critsrion proposed by Piwnik and Plata in DEFORM 2D environment. The innovative aspect of this research is that it is possible to actually weld the material considering what happens to the billet material itself. This procedure was used to evaluate the influence of die geometrical parameters on the welding formation. A simplified 2D extrusion model was used to reduce calculation time and to focus the attention just on what happens in the welding region. The results show that the implemented procedure is capable to monitor the weld..
La sicurezza in fonderia
No full textDa una indagine ISPESL risulta come più del 10% degli infortuni sul lavoro abbiano origine dall’uso di macchine, macchine mobili ed apparecchi. Ambienti particolarmente ostili, come fonderie ed acciaierie, presentano una elevata ricorrenza di tali infortuni, alcuni dei quali con esito mortale. I rischi tradizionalmente conosciuti sono attualmente ben controllati (con protezioni sugli organi mobili, ad esempio, o con sistemi di comando bimano). Comunque emergono sempre nuovi rischi connessi con lo sviluppo di nuove tecnologie e macchine od impianti sempre più complessi. Nella progettazione delle macchine è quindi necessario tener conto dei vincoli connessi alla sicurezza dei lavoratori
Experimental and simulative applications of double sheet hydroforming
No full textIn the automotive field the sheet hydroforming technique is used to produce hoods, fender panels, panels and box-type elements like tanks or differential covers, but its limit is the high cycle time. As a consequence double sheet hydroforming can be a valid improvement for reducing the production time by 50%. The final part quality, in terms of dimensions, can be obtained in the subsequent process operations (i.e.: trimming) so as to calibrate the sheet which is not directly in contact with the die. This paper presents the comparison between simulative and experimental results of double sheet direct hydroforming. The FEM code used has already been validated when directly hydroforming the same single part (Ceretti et al., 2003). This was the starting point to implement a new simulation campaign coupled with new experimental tests. In this research three different sheet material combinations are considered in order to investigate their behaviour. The good agreement between simulative and experimental results is the confirmation of the well designed FEM model. The accuracy of the final part shapes means this type of hydroforming can be considered a valid alternative, with respect to the classical method, for obtaining, in one shot, components with a good finishing surface and with a consequent saving in the production time
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