No abstract

In an increasing number of aggressive enterprise world, "time to market" concerning products has come to be a solution element because of enterprise success. There are exceptional techniques so expect layout mistakes or open products concerning the need between much less time. Among the most used methodologies in the design and setting about stability the requirements, Quality Function Deployment (QFD) and Design for Six Sigma (DFSS) execute remain used. In the prototyping phase, such is feasible in imitation of tackle the rising science regarding additive manufacturing. Today, three-dimensional stamping is in the meanwhile used as a rapid prototyping technique. However, the actual challenge that enterprise is going through is the use of these machineries for large-scale production about parts, at last viable along current HP Multi fusion. The aim of this article is to study the interactive design and engineering applied to the entire product development process taking advantage of the most modern models and technologies for the final realization of a case study that involves the design and prototyping of an innovative multifunctional fan (Lamp, Aroma Diffuser and fan) through the Multi Jet Fusion of HP. To begin with, issues related to the DFSS, the QFD and their application to identify the fan requirements are explored. Once the requirements have been defined, the modern CAD design systems and the CAE systems for the validation of the case study will be analyzed and applied. Finally, HP's Multi Jet Fusion methodology and design rules for additive manufacturing will be analyzed in detail, trying to exploit all the positive aspects it offers.

No abstract

The present work aims to propose a new approach for defining interactive user manual in complex assemblies, using a new enabling technology of Industry 4.0, i.e. Augmented Reality. The AR environment supports the user in stepby-step assembly on-the-fly. The study of this method, suitable to realize the assembly of parts, is a stimulating engineering mission, which can take advantage from the latest innovations in imagining technologies and computer graphics. In the present paper, a proposal for an innovative method based on Augmented Reality useful to support the components' assembly is suggested. The methodology illustrated is based upon a four steps process: at the beginning, the designer performs the assembly structure through a CAD system. In a second time, an unexperienced user assembles the same parts without any suggestion: the differences between two assembly sequences are documented and broken down in order to distinguish critical points in the assembly. Finally, a virtual user manual is shaped in Augmented Reality environment. The assembly is then performed by the same unexperienced user, guided by the AR tool. When the end user practices the instrument, the location of the item to assemble is perceived by tracking the finger position of the user itself. In order to help the end-user in the assembly procedure, a series of symbols and texts is added to the external scene. In this paper a case study based on the assembly of a scale model has been developed to evaluate the methodology. After an evaluation process, the procedure seems to be feasible and presents some advantages over the state-of-the-art methodologies proposed by literature.

No abstract

Over the past decades, the technological development in the medical field, coupled with the ongoing scientific research, has led to the development and improvement of dental prostheses supported by screw-retained metal frameworks. A key point in the manufacture of the framework is the achievement of a passive fit, intended as the capability of an implant-supported reconstruction to transmit minimum strain to implant components as well as to the surrounding bone, when subject to any load. The fitting of four different kinds of screw-retained metal frameworks was tested in this article. They differ both in materials and manufacturing process: two frameworks are made by casting, one framework is made by computer-aided design and computer-aided manufacturing and one framework is made by electric resistance spot welding (WeldONE, DENTSPLY Implants Manufacturing GmbH, Mannheim, Germany). The passivity of the frameworks was evaluated on the entire system, composed of a resin master cast, the implant analogues embedded in the cast and the frameworks. Strains were recorded by means of an electrical strain gauge connected to a control unit for strain gauge measurements. The experimental tests were carried out in the laboratories of the Department of INdustrial engineering at the University of Bologna. The results of the test campaigns, which compared three samples for each technological process, showed that no significant differences exist between the four framework types. In particular, the frameworks made by the resistance welding approach led to a mechanical response that is well comparable to that of the other tested frameworks.

No abstract

Recently, the approach that defines the total life cycle assessment (LCA) and the end of life (EoL) in the early design phases is becoming even more promising. Literature evidences many advantages in terms of the saving of costs and time and in the fluent organization of the whole design process. Design for disassembly (DfD) offers the possibility of reducing the time and cost of disassembling a product and accounts for the reusing of parts and of the dismantling of parts, joints, and materials. The sequence of disassembly is the ordered way to extract parts from an assembly and is a focal item in DfD because it can deeply influence times and operations. In this paper, some disassembly sequences are evaluated, and among them, two methods for defining an optimal sequence are provided and tested on a case study of a mechanical assembly. A further sequence of disassembly is provided by the authors based on experience and personal knowledge. All three are analyzed by the disassembly order graph (DOG) approach and compared. The operations evaluated have been converted in time using time measurement units (TMUs). As result, the best sequence has been highlighted in order to define a structured and efficient disassembly.