Special Issue on Future Digital Design and Manufacturing:Embracing Industry 4.0 and Beyond

Industry 4.0 as referred to the fourth industrial revolution has endorsed in several national manufacturing initiatives or development plans such as in Germany, the UK, USA and China. A set of important pervasive and secondary technologies for future manufacturing activities have been identified such as additive manufacturing, sensor technology,

Design and Manufacturing Strategies for Fused Deposition Modelling in Additive Manufacturing:A Review

Although several research works in the literature have focused on studying the capabilities of additive manufacturing(AM) systems, few works have addressed the development of Design for Additive Manufacturing(DfAM) knowledge,tools, rules, and methodologies, which has limited the penetration and impact of AM in industry. In this paper a comprehensive review of design and manufacturing strategies for Fused Deposition Modelling(FDM) is presented.Consequently, several DfAM strategies are proposed and analysed based on existing research works and the operation principles, materials, capabilities and limitations of the FDM process. These strategies have been divided into four main groups: geometry, quality, materials and sustainability. The implementation and practicality of the proposed DfAM is illustrated by three case studies. The new proposed DfAM strategies are intended to assist designers and manufacturers when making decisions to satisfy functional needs, while ensuring manufacturability in FDM systems.Moreover, many of these strategies can be applied or extended to other AM processes besides FDM.

Future Digital Design and Manufacturing Technologies for Manufacturing Innovation:Embracing Industry 4.0 and Beyond

Industry 4.0 as referred to a fourth industrial revolution has endorsed in several national manufacturing development plans such as in Germany, the UK, and China. A set of important pervasive and secondary technologies for future manufacturing activities have been identified such as additive manufacturing, sensor technology, big data analytics, Internet of things, robotics, cloud computing, and nanotechnology.

Special Issue on Future Digital Design and Manufacturing:Embracing Industry 4.0 and Beyond-Part Ⅱ

Digital design and manufacturing have been under pinned by digital modeling, simulation, and automation controls for decades. Under the new market requirement of mass customized products and services, the advancements in artificial intelligence （AI）, smart technology, virtual reality （VR）, big data, digital twin, robotics and human-centered design are becoming driving forces for the development of future digital design and manufacturing. This special issue focuses on the future digital design and manufacturing especially under the Industry 4.0 framework and beyond. This editorial introduces the papers in this special issue, which linked to the International Workshop on Digital Design and Manufacturing Technologies - Embracing Industry 4.0 and Beyond at Northumbria University in Newcastle, UK, held on 12-13 April 2016. In the Part I of the issue [1], there are 13 papers published in 2016, Vol- ume 29, No 6 of the Chinese Journal of Mechanical Engineering （this journal）.

Design and Fabrication of a Three Dimensional Commemorative Artistic Plaque

In this paper, design and fabrication of a commemorative plaque are described and presented. The plaque was fabricated to honour the memory of the 14 women massacred at L＇Ecole Polytechnique in Montreal. This plaque is the result of a project partnership between the Faculties of Engineering and Fine Arts, and was sponsored by the Office of the Vice-President Academic and Provost. An art design was selected through a contest coordinated by the Visual Arts Departmment. The selected art design was then turned over to the Mechanical Engineering Department to be converted to a 3-dimensional （3D） solid model and then eventually fabricated on a computer numerical control （CNC） milling machine. The fabricated plaque was unveiled during the December 2010 Memorial event at UVic.

CONCURRENT PRODUCT PORTFOLIO PLANNING AND MIXED PRODUCT ASSEMBLY LINE BALANCING

Reconfigurable products and manufacturing systems have enabled manufacturers to provide ＂cost effective＂ variety to the market. In spite of these new technologies, the expense of manufacturing makes it infeasible to supply all the possible variants to the market for some industries. Therefore, the determination of the right number of product variantsto offer in the product portfolios becomes an important consideration. The product portfolio planning problem had been independently well studied from marketing and engineering perspectives. However, advantages can be gained from using a concurrent marketing and engineering approach. Concurrent product development strategies specifically for reconfigurable products and manufacturing systems can allow manufacturers to select best product portfolios from marketing, product design and manufacturing perspectives. A methodology for the concurrent design of a product portfolio and assembly system is presented. The objective of the concurrent product portfolio planning and assembly system design problem is to obtain the product variants that will make up the product portfolio such that oversupply of optional modules is minimized and the assembly line efficiency is maximized. Explicit design of the assembly system is obtained during the solution of the problem. It is assumed that the demand for optional modules and the assembly times for these modules are known a priori. A genetic algorithm is used in the solution of the problem. The basic premise of this methodology is that the selected product portfolio has a significant impact on the solution of the assembly line balancing problem. An example is used to validate this hypothesis. The example is then further developed to demonstrate how the methodology can be used to obtain the optimal product portfolio. This approach is intended for use by manufacturers during the early design stages of product family design.

Replacement of Unesthetic Posterior Metal Crowns with Monolithic Zirconia Crowns: A Case Report

Advances in metal-free materials and the popularization of Computer-Aided Design and Manufacturing (CAD/CAM) have led to the wide clinical use of all-ceramic crowns for esthetic restorations. A 72-year-old woman presented to our hospital with unesthetic restorations on the right upper and lower posterior teeth. Intraoral examination revealed poorly fitting metal crown margins. Defective prostheses were removed, and provisional restorations were provided to stabilize the mandibular position. Optical impressions and the maxillomandibular relationship were recorded using an intraoral scanner, and monolithic zirconia crowns were fabricated using CAD/CAM technology for complete veneer crown restorative treatment. Occlusal examination revealed an improvement in occlusal force distribution at initial examination (right side: 33.5%, left side: 66.5%) after placement of the zirconia crowns (right side: 54.9%, left side: 45.1%). Occlusal force and occlusal force distribution area also showed an increasing trend. The Oral Health Impact Profile short form (OHIP-14) score decreased from 7 points at initial examination to 0 points after prosthodontic treatment. Appropriate diagnosis and treatment planning contributed to the increased occlusal force and balanced occlusal force distribution. Therefore, the present case indicates the potential of monolithic zirconia crowns to achieve both esthetic and stable functional outcomes.

Recent progresses on designing and manufacturing of bulk refractory alloys with high performances based on controlling interfaces

Refractory alloys such as tungsten and molybdenum based alloys with high strength,thermal/electrical conductivity,low coefficient of thermal expansion and excellent creep resistances are highly desirable for applications in nuclear facilities,critical components in aerospace and defense components.However,the serious embrittlement limits the engineering usability of some refractory alloys.A lot of research results indicate that the performances of refractory alloys are closely related to the physical/chemical status,such as the interface dimension,interface type,interface composition of their grain boundaries(GBs),phase boundaries(PBs)and other interface features.This paper reviewed the recent progress of simulations and experiments on interface design strategies that achieve high performance refractory alloys.These strategies include GB interface purifying/strengthening,PB interface strengthening and PB/GB synergistic strengthening.Great details are provided on the design/fabrication strategy such as GB interface controlling,PB interface controlling and synergistic control of multi-scaled interfaces.The corresponding performances such as the mechanical property,thermal conductivity,thermal load resistance,thermal stability,irradiation resistance,and oxidation resistance are reviewed in the aspect to the effect of interfaces.In addition,the relationships between these interfaces and material properties are discussed.Finally,future developments and potential new research directions for refractory alloys are proposed.

Research on steel-fibber polymer concrete machine tool structure

Researched on the design and manufacturing of machine tool bed made by Steel-fibber Polymer Concrete(SFPC),which analyzed the static,dynamic and thermal performances of the bed.The results of study prove that machine tool bed made with SFPC is much more superiority than made in cast iron in dynamic and thermal perform- ances,and is more superiority then made in Polymer Concrete (PC) in static perform- ances.It can be concluded that the static,dynamic and thermal properties of machine tool can be improved by manufacturing machine tool bed with SFPC.Also SFPC machine tool bed posses some other advantages in the following: short development time,simple pro- duction process,reducing cost cost,saving energy,iron and steel.

CFD Simulation of Air Flow Behaviour at Different Flow Rates in a Turkish Woodwind Instrument (Turkish Treble Recorder)

In musical instruments, the geometric design and material features of the instrument are the most important factors that determine the sound characteristics of the instrument. Traditional replication and experiment-based handcrafting methods are predominant in the production of Turkish Folk Music wind instruments. The instrument manufacturing and standardization approaches, which include the relevant rules of physics and engineering practices, are limited purely to prototype studies for scientific research purposes. It is almost impossible to find studies on Turkish Folk Music wind instrument design and production involving computer aided design and engineering applications. In this study, an example Turkish woodwind instrument, the Turkish Treble Recorder (dilli kaval) is considered, and the air flow behaviour and acoustic (sound) power magnitudes that occur at different air flow rates are simulated in a computer environment using a Computational Fluid Dynamics (CFD) simulation technique. In the study, numerical and visual outputs related to air behaviour at different air flow rates that may be used in the instrument manufacturing phases were obtained. Acoustic power level was also measured experimentally. Simulation outputs (the acoustic power level) were compared to experimental results in order to validate the simulation results. The comparison revealed that the highest relative difference was calculated as 13.32(%). This value indicated that the simulation results were reasonably consistent with the results of the experimental measurement. Additionally, this study was constructed as a case study that may provide reference for future research studies in this field.

Face transplantation for massive mandibular defects: considerations for allograft design and surgical planning

Modern face transplant techniques have advanced to allow for the transfer of vascularized skeletal components in addition to overlying soft tissue.This represents significant opportunity for individuals with mandibular defects that are not amenable to traditional reconstruction.Care must be taken when planning and executing transplants with these complex grafts,as satisfactory functional and aesthetic outcomes rely on achieving proper spatial relationships between the mandible,skull base,and midface.Which donor skeletal elements are included in the allograft and how they are harvested are important considerations in this planning and are associated with controversy.To optimize outcomes in the reconstruction of single-jaw defects,some advocate for transplantation of only the affected jaw while others support bimaxillary transplantation.Clinical evidence in this debate is not conclusive at this time.In current practice,including donor dentoalveolar anatomy by utilizing a bilateral sagittal split osteotomy of the mandible is favored to optimize outcomes such as dental occlusion.It has been suggested that harvesting the mandible at the level of the condyle or even the temporal bone may also be possible and may improve temporomandibular joint-related outcomes.Despite encouraging preclinical evidence,these strategies remain controversial.After allograft design,successful mandibular reconstruction with face transplantation relies on surgical precision in the donor and recipient procedures.Computerized surgical planning,computer-aided design and manufacturing,and intraoperative navigation are technologies currently in use to mitigate operative complexity.Results in both cadaveric and clinical face transplantations suggest these technologies are reliable and beneficial,although some room for improvement remains.

Methodology and Technology for Design to Cost

Product cost is one of the most important factors affecting product market share. Traditionally, product costs are estimated after they are manufactured. However, in this way, the best opportunity to control product cost is lost. In this paper, a method trying to reduce product cost at the design stage is proposed. This method is called Design to Cost (DTC). According to this method, product structure can be optimized with the application of value engineering and Design for Manufacturing/Assembly (DFMA) criteria in the conceptual stage of product design. During embodiment design, products are evaluated economically on the basis of the product model which includes manufacturing, assembly and test cost information. According to the results, products are redesigned before manufacture, and the production cost is reduced.

THE OBJECT-ORIENTED INTELLIGENT PROGRAMMING IN CAD/CAM

Design and manufacture organizations currently suffer from a number of problems that aignificantly affect their productivity.Despite their fragmented efforts to automate portioas of operations,they still suffer from 'islands' of designing and manufacturing automation,long lead time for semi-custom proposals and engineering work, lengthy cycles of product development and introduction into the market,and low morale due to boring,repetitive engineering and industrial design activities.Thereby,the integration of design and manufacturing poses to the CAD/CAM researchere a series of challenges.The paper introduces a methodology that allows for the integration of product design with manufacturing process planning and the application of a new software technology known as 'Object-Oriented Intelligent Programming' .The task is achieved through an object-oriented intelligent CAD/CAM environment where a design model from the CAD system can be analysed, and manufacturing process plans with specifications of machining can be automatically determined.The manufacturing information of a part is extracted from the 3D geometric model and the 2D engineering drawing,thus,both geometric and non-geometric attributes of a part can be obtained.

CAD/CAM for scalable nanomanufacturing:A network-based system for hybrid 3D printing

Micro-and nano-structuring have been highlighted over several decades in both science and engineering fields.In addition to continuous efforts in fabrication techniques,investigations in scalable nanomanufacturing have been pursued to achieve reduced feature size,fewer constraints in terms of materials and dimensional complexity,as well as improved process throughput.In this study,based on recent micro-/nanoscale fabrication processes,characteristics and key requirements for computer-aided design and manufacturing(CAD/CAM)systems for scalable nanomanufacturing were investigated.Requirements include a process knowledge database,standardized processing,active communication,adaptive interpolation,a consistent coordinate system,and management of peripheral devices.For scalable nanomanufacturing,it is important to consider the flexibility and expandability of each process,because hybrid and bridging processes represent effective ways to expand process capabilities.As an example,we describe a novel CAD/CAM system for hybrid three-dimensional(3D)printing at the nanoscale.This novel hybrid process was developed by bridging aerodynamically focused nanoparticle printing,focused ion beam milling,micromachining,and spincoating processes.The system developed can print a full 3D structure using various inorganic materials,with a minimum process scale of 50 nm.The most obvious difference versus CAD/CAM at‘conventional’scales is that our system was developed based on a network to promote communication between users and process operators.With the network-based system,it is also possible to narrow the gap among different processes/resources.We anticipate that this approach can contribute to the development of CAD/CAM for scalable nanomanufacturing and a wide range of hybrid processes.