Search results for " Manufacturing"
showing 10 items of 2018 documents
Theatrical virtual acoustic rendering with head movement interaction
2019
AbstractNowadays, the use of virtual reality/virtual acoustics (VR/VA) in archaeology for rendering lost buildings is an important topic in the cultural heritage field. Moreover, the addition of additional senses apart from the sight increases the feeling of immersion in virtual environments. The aim of this paper is to show the interaction work developed in a VA system, based on Unity and FMOD, the graphical and acoustical reconstruction of an ancient building and the development of a VR goggles with headphones to render 3D audio and video interactively. This system has been implemented to render auralizations in a binaural system and has been applied to the renderization of an old and los…
Motion-control techniques of today and tomorrow: a review and discussion of the challenges of controlled motion
2020
Motion-control technologies are at the core of multiple mechatronic products and applications. Wherever actuated motion takes place in machines and components, either position or force setting (or trajectory tracking), or even a combination of both, are demanded from the control system. In high-performance mechatronic systems, including micro- and/or nanoscale motion (such as data-storage devices, machine tools, manufacturing tools for electronics components, and industrial robots), the required specifications in motion performance, such as response/settling time and trajectory/settling accuracy, should be sufficiently achieved [1].
Computer-Aided Simulation of Die Filling Processes
1989
Summary A numerical method for analysing the filling of axisymmetrical dies of complex shape is proposed. The method, which is a further development of a LP finite element model, is able to take into account the contact conditions directly in the mathematical formulation of the problem. In such a way the solution of the die filling process is obtained by solving a LP problem, avoiding problems of numerical convergence and the heavier calculations requested by other iterative methods.
Dual phase titanium alloy hot forging process design: experiments and numerical modeling
2015
Titanium alloys are considered desirable materials when both good mechanical properties and weight reduction are required at the same time. This class of materials is widely used in those fields (aeronautics, aerospace) in which common steels and light-weight materials, e.g., aluminum alloys, are not able to satisfy all operative service conditions. During the last decade, forging of titanium alloys has attracted greater attention from both industrial and scientific/academic researchers because of their potential in providing a near net shaped part with minimal need for machining. In this paper, a numerical model of the forging sequences for a Ti-6Al-4V titanium alloy aerospace component is…
Finite-element simulation of residual stress induced by split-sleeve cold-expansion process of holes
2008
A three-dimensional finite-element simulation was conducted for a split-sleeve cold-expansion process in order to determine the residual stress field around an expanded hole. The commercial FEA software DEFORM-3D™, a Lagrangian implicit code designed for metal forming processes, was used to model the cold-expansion process of a fastener hole. The results show a through-thickness residual stress field in good agreement with the analytical solution developed by Guo. Moreover, the simulation has highlighted the effect of the split sleeve and the plate thickness on the residual stress field. © 2007 Elsevier B.V. All rights reserved.
Analytical bonding criteria for joint integrity prediction in friction stir welding of aluminum alloys
2014
Abstract In this study, two bonding criteria, previously used for porthole die extrusion, are applied to FSW starting from the local value of the main field variables calculated through a specifically developed 3D numerical model of the process. Their applicability and effectiveness have been assessed through an experimental and numerical campaign carried out with the main process parameters varying in a wide range. The pressure–time–flow criterion was demonstrated to be better suited for FSW processes when large welding speed is used.
Volatile Compounds in Red Wines Processed on an Industrial Scale by Short Pre-fermentative Cold Maceration
2012
Nero d’Avola and Shiraz grapes were subjected to pre-fermentative cold maceration at 4°C for about 24 h in industrial winemaking, in order to evaluate the effects of the pre-treatment on aroma profile. The volatile compounds were identified by gas chromatography-mass spectrometry and grouped into 14 chemical families 4 and 9 months after bottling. Principal components analysis (PCA) plots of the volatile compounds showed clear separation among wines from the Shiraz and Nero d’Avola varieties. For instance, Shiraz wines were characterized along the PC1 axe by esters of organic acids, norisoprenoids and C6 alcohols, while Nero d’Avola wines were characterized by acetates and monoterpenic oxid…
Economic Robustness Analysis of Adaptive Chart Schemes for Monitoring the Total Nonconformities Number in Inspection Units
2015
In recent years, a variety of enhanced schemes for the c chart have been developed aimed at the effectiveness improving of the related statistical process control (SPC) procedures. However, the performance of such chart schemes can be very sensitive to values assumed for some operating and cost parameters, in particular to the considered process shift magnitude arising from out-of-control conditions. In such a circumstance, the effectiveness of such chart schemes can be subjected to substantial reductions when they are implemented in operative contexts given that, in practice, such value is unknown and it can be very difficult to accurately estimate. For this reason, in the present paper i…
Characterisation and optimal design of a new double sampling <i>c</i> chart
2019
This paper proposes a new double sampling scheme for c control chart (DS-c), which was designed to improve the performance of c chart or to reduce the inspection cost. The mathematical expression required to do an exact evaluation of ARL and ASN is deduced. Further, a bi-objective genetic algorithm is implemented to obtain the optimal design of the DS-c scheme. This optimisation is aimed to simultaneously minimising the error probability type II and the ASN, guaranteeing a desired level for the error probability type I. A performance comparison between the double sampling (DS), fixed parameters (FP), variable simple size (VSS) and exponential weighted moving average (EWMA) schemes for the c…
Thallium in Wein — Spurenelement-Vinogramm des Thalliums
1984
Das Ultra-Spurenelement Thallium ist regelmasig in geringsten Gehalten in Wein enthalten, in Rotwein durchschnittlich 0,2 μg Tl/l, mehr als in Weisweinen mit durchschnittlich 0,1 μg Tl/l. Uber Herkunft und Verhalten solcher geringsten Thallium-Gehalte konnen einige Hinweise aus den zusatzlichen Untersuchungen (Boden, Standort, Dungemittel, Einflus der Kellertechnik) gegeben werden. Eine Korrelation von Thallium mit Kalium ist bekannt; es kann aber daruber hinaus gezeigt werden, das ahnlich dem Rubidium gewisse Traubenteile (Beere, Beerenfleisch, Schale) reicher an Thallium sind und auf diese Weise hohere Gehalte, insbesondere in Rotweinen, erklart werden konnen. Geringfugig hohere Thallium-…