Showing papers in "Cirp Annals-manufacturing Technology in 2016"
TL;DR: In the case of aircraft components, AM technology enables low-volume manufacturing, easy integration of design changes and, at least as importantly, piece part reductions to greatly simplify product assembly.
Abstract: The past few decades have seen substantial growth in Additive Manufacturing (AM) technologies. However, this growth has mainly been process-driven. The evolution of engineering design to take advantage of the possibilities afforded by AM and to manage the constraints associated with the technology has lagged behind. This paper presents the major opportunities, constraints, and economic considerations for Design for Additive Manufacturing. It explores issues related to design and redesign for direct and indirect AM production. It also highlights key industrial applications, outlines future challenges, and identifies promising directions for research and the exploitation of AM's full potential in industry.
1,132 citations
Hungarian Academy of Sciences1, Budapest University of Technology and Economics2, Fraunhofer Institute for Manufacturing Engineering and Automation3, University of Stuttgart4, National Institute of Advanced Industrial Science and Technology5, Pennsylvania State University6, Technische Universität München7, Fraunhofer Society8, RWTH Aachen University9, University of Tokyo10
TL;DR: There are significant roots in general and in particular to the CIRP community – which point towards CPPS, and expectations towards research in and implementation of CPS and CPPS are outlined.
Abstract: One of the most significant advances in the development of computer science, information and communication technologies is represented by the cyber-physical systems (CPS). They are systems of collaborating computational entities which are in intensive connection with the surrounding physical world and its on-going processes, providing and using, at the same time, data-accessing and data-processing services available on the Internet. Cyber-physical production systems (CPPS), relying on the latest, and the foreseeable further developments of computer science, information and communication technologies on one hand, and of manufacturing science and technology, on the other, may lead to the 4th industrial revolution, frequently noted as Industrie 4.0. The paper underlines that there are significant roots in general – and in particular to the CIRP community – which point towards CPPS. Expectations towards research in and implementation of CPS and CPPS are outlined and some case studies are introduced. Related new R&D challenges are highlighted.
1,123 citations
TL;DR: An overview of major cryogenic manufacturing processes, summarizing the state-of-the-art and significant developments during the last few decades, is presented in this article, with a summary of historic perspectives, including definitions, scope, and analysis of process mechanics and material performance covering tribological and thermo-mechanical interactions.
Abstract: Cryogenically assisted manufacturing processes are emerging as environmentally-benign, toxic-free, hazardless operations, producing functionally superior products. This paper presents an overview of major cryogenic manufacturing processes, summarizing the state-of-the-art and significant developments during the last few decades. It begins with a summary of historic perspectives, including definitions, scope, and proceeds to analysis of process mechanics and material performance covering tribological and thermo-mechanical interactions, followed by surface integrity, product quality and performance in cryogenic manufacturing. Process analysis and applications includes machining, forming and grinding. Economic, safety and health issues are then discussed. Finally, progress in developing predictive performance models and future outlook are presented.
306 citations
TL;DR: Foundations and technologies required for continuous maintenance within the Industry 4.0 context are presented and the role of IoT, standards and cyber security are identified.
Abstract: High value and long life products require continuous maintenance throughout their life cycle to achieve required performance with optimum through-life cost. This paper presents foundations and technologies required to offer the maintenance service. Component and system level degradation science, assessment and modelling along with life cycle ‘big data’ analytics are the two most important knowledge and skill base required for the continuous maintenance. Advanced computing and visualisation technologies will improve efficiency of the maintenance and reduce through-life cost of the product. Future of continuous maintenance within the Industry 4.0 context also identifies the role of IoT, standards and cyber security.
222 citations
TL;DR: Abrasive fine-finishing technology is often applied as a final finishing process, and the selection of the right technology is crucial to obtaining the desired performance of functions such as fatigue life.
Abstract: Abrasive fine-finishing technology is often applied as a final finishing process, and the selection of the right technology is crucial to obtaining the desired performance of functions such as fatigue life. This paper begins with classifications of the technology along with fundamentals and brief histories of the individual methods. The material removal mechanisms, specific energies, and finishing characteristics of the various technologies are summarized giving assessments of the surfaces created by them. Guidelines developed for selecting the appropriate methods, and case studies illustrate the effectiveness of various methods. This paper ends with a discussion of the future prospects of the technology. (C) 2016
163 citations
TL;DR: In this paper, the authors proposed to use Life Cycle Assessment (LCA) method and associate decision criteria to support the selection of manufacturing strategies for an aeronautic turbine.
Abstract: Additive manufacturing technologies are opening new opportunities in term of production paradigm and manufacturing possibilities. Nevertheless, in term of environmental impact analysis supplementary research works require to be made in order to compare and evaluate them with traditional manufacturing processes. In this article, we propose to use Life Cycle Assessment (LCA) method and to associate decision criteria to support the selection of manufacturing strategies for an aeronautic turbine. The dimensionless criteria allow to define environmental trade-offs between additive and subtractive methods. This study provides an approach generalizable to other parts and processes.
152 citations
TL;DR: A framework of analysis is presented for understanding closed-loop control in metal forming, allowing an assessment of current and future developments in actuators, sensors and models, and a discussion of likely developments.
Abstract: Metal forming processes operate in conditions of uncertainty due to parameter variation and imperfect understanding. This uncertainty leads to a degradation of product properties from customer specifications, which can be reduced by the use of closed-loop control. A framework of analysis is presented for understanding closed-loop control in metal forming, allowing an assessment of current and future developments in actuators, sensors and models. This leads to a survey of current and emerging applications across a broad spectrum of metal forming processes, and a discussion of likely developments.
133 citations
TL;DR: In this article, the authors compared various destructive and non-destructive testing methods, ranging from global to local observation techniques and from quick low-cost to expensive time-consuming analyses.
Abstract: This study focuses on the comparison of porosity testing methods for the quality assessment of selective laser melted parts. Porosity is regarded as important quality indicator in metal additive manufacturing. Various destructive and non-destructive testing methods are compared, ranging from global to local observation techniques and from quick low-cost to expensive time-consuming analyses. Forty test specimens were produced using five varying control factors. The experimental results show that Archimedes and CT methods compare well, Archimedes can be deployed to inspect parts in small series and CT pre- and post-cut analysis show that post-cut porosity results are systematically higher
121 citations
TL;DR: All surface modification processes using guided tools with periodic or continuous contact to the workpiece are compared and a systematic description by comparing the different technologies and the proposed standardized nomenclature is presented.
Abstract: A wide range of surface modification processes has been developed over the past decades. Beside the well-established processes such as shot peening, there are other emerging surface modification processes such as machine hammer peening with a potential of applications that still needs to be evaluated. Therefore, all surface modification processes using guided tools with periodic or continuous contact to the workpiece are compared in this paper. After a classification of the processes, the paper presents a systematic description by comparing the different technologies and it explains the proposed standardized nomenclature. It identifies the relevant physical mechanisms of the surface modifications processes and it compares the influences on surface roughness, residual stresses, work hardening and microstructure. One section is dedicated to the need of an accompanying quality assurance. Furthermore, the capabilities of different process simulation approaches are analyzed with respect to process mechanisms and the resulting surface layer characteristics. The service performance such as fatigue life, corrosion resistance, friction and wear are discussed based on best practice results. Finally, the paper discusses the actual and potential applications of surface modification processes: surface strengthening, post welding treatments, smoothing of tools and molds as well as surface structuring and embedding of coating materials.
113 citations
TL;DR: In this article, high voltage fragmentation, originally conceived for fracturing rocks was investigated as a potential process for composite recycling, and compared with its competitor, mechanical recycling, in terms of effectiveness in separating composite phases, energy demand and recyclate quality.
Abstract: Global increase of composite waste urgently requires innovative recycling technology. The three dimensional cross-linked structure makes melting and remoulding of thermoset composite impossible. In this study, high voltage fragmentation, originally conceived for fracturing rocks was investigated as a potential process for composite recycling. It was then benchmarked against its competitor, mechanical recycling. The investigation covered effectiveness in separating composite phases, energy demand and recyclate quality. The work is a new contribution to the performance evaluation of key technologies for rapid recycling glass fibre thermoset composites, a major challenge for manufacturing and end-of-life product waste.
68 citations
TL;DR: In this article, a decision support system helps to take decisions about the depth of disassembly and the organization of the disassembly system, depending on the pre-process measurement of the key quality characteristics of the product to be disassembled.
Abstract: The quality of post-consumer products is one of the major sources of uncertainty in disassembly systems. This paper develops a methodology to design disassembly lines under variability of the End-of-Life product quality, with the objective to maximize the profit. This decision support system helps to take decisions about the depth of disassembly and the organization of the disassembly system, depending on the pre-process measurement of the key quality characteristics of the product to be disassembled. The industrial benefits are demonstrated in a real industrial case focused on the remanufacturing of mechatronic parts in the automotive industry.
TL;DR: In this paper, five different coatings and two PCBN grades were evaluated when high speed turning Inconel 718. Tool life was 40% higher when employing TiSiN coated over uncoated inserts at 200m/min.
Abstract: Five different coatings and two PCBN grades were evaluated when high speed turning Inconel 718. Tool life was 40% higher when employing TiSiN coated over uncoated inserts at 200 m/min. When operating at 300–450 m/min however, coatings provided no appreciable benefit. Workpiece surface roughness varied between ∼0.25 and 1.05 μm Ra while cutting forces were
TL;DR: In this article, the authors present concrete examples from industrial production, in which the added value of metrology in manufacturing is discussed and quantified, and the focus of the paper is on the improved effectiveness of metrologies when used at product and process design stages, as well as the improved accuracy and efficiency of manufacturing through better measuring equipment and process chains with integrated metrology.
Abstract: In streamlined manufacturing systems, the added value of inspection activities is often questioned, and metrology in particular is sometimes considered only as an avoidable expense. Documented quantification of economic benefits of metrology is generally not available. This work presents concrete examples from industrial production, in which the added value of metrology in manufacturing is discussed and quantified. Case studies include: general manufacturing, forging, machining, and related metrology. The focus of the paper is on the improved effectiveness of metrology when used at product and process design stages, as well as on the improved accuracy and efficiency of manufacturing through better measuring equipment and process chains with integrated metrology for process control.
TL;DR: A method was developed to use data from an inertial measurement unit for identification of changes in the translational and angular errors due to axis degradation, and it was revealed that the IMU-based method was capable of measuring geometric errors with acceptable test uncertainty ratios.
Abstract: Machine tools degrade during operations, yet knowledge of degradation is elusive; accurately detecting degradation of linear axes is typically a manual and time-consuming process. Manufacturers need automated and efficient methods to diagnose the condition of their machine tool linear axes with minimal disruptions to production. A method was developed to use data from an inertial measurement unit (IMU) for identification of changes in the translational and angular errors due to axis degradation. A linear axis testbed, established for the purpose of verification and validation, revealed that the IMU-based method was capable of measuring geometric errors with acceptable test uncertainty ratios.
TL;DR: In this article, a hybrid dieless sheet metal forming process, electrically assisted mixed double-sided incremental forming (E-MDSIF), is proposed to manufacture difficult-to-form Ti6Al4V sheets.
Abstract: Incremental forming can be an alternative manufacturing means in producing biomedical parts characterized by the need of patient-specific geometry A novel hybrid dieless sheet metal forming process, electrically-assisted mixed double-sided incremental forming (E-MDSIF), is proposed to manufacture difficult-to-form Ti6Al4V sheets E-MDSIF is a spark-free technique shown to increase the formability and the geometric accuracy while decreasing the forming force The effects of the electrical process on microstructure, micro-hardness and surface roughness of the formed parts are investigated Additionally, comparisons between E-MDSIF and the conventional E-ISF processes are illustrated based on fundamental mechanics Limitations and potential applications are presented
TL;DR: In this paper, a virtual spindle based tool servo (VSTS) diamond turning method is proposed for the generation of discontinuously structured microoptics arrays. But, the VSTS is not suitable for high dimensional surfaces.
Abstract: We propose a virtual spindle based tool servo (VSTS) diamond turning method for the generation of discontinuously structured microoptics arrays. Uniqueness of the VSTS is that a virtual spindle axis (VSA) is constructed at any specified position by combining the multiple translational and rotational servo motions of the machine tool. Thereby, we can array the microstructure cell with a shape that can be generated in fast- or slow tool servo by controlling the VSA to sequentially pass through the centre of each cell. Feasibility of this technique is demonstrated by fabricating discontinuous microoptics arrays on both planar and freeform surfaces.
TL;DR: In this article, a Shamrock geometry is proposed leading to the development of a novel improved thickness correction model that incorporates wall angle, in-plane curvature, and tool direction.
Abstract: The success of a toolpath in double-sided incremental forming (DSIF) is strongly related to the specified tool gap. It is hypothesized in this work that maintained contact between tools and the sheet can improve the distribution of sheet thickness and hence, improve material formability and prevent premature fracture. Simulation and experimental studies reveal that thickness prediction models solely dependent on the local wall angle are inadequate for general part geometries. A ‘Shamrock’ geometry is proposed leading to the development of a novel improved thickness correction model that incorporates wall angle, in-plane curvature, and tool direction.
TL;DR: In this paper, an integrated tool has been developed based on a generic discrete event simulation (DES) factory model, which is linked to the company's resource planning system in order to not only assess the sustainability performance of each company's as-is operations, but also optimise their future performance.
Abstract: Sustainability assessment needs to be embedded into manufacturers’ daily operations for continuous improvement. Existing factories, especially small and medium enterprises (SMEs), often lack infrastructure and capital to enable such regular assessment. An integrated tool has been developed based on a generic discrete event simulation (DES) factory model, which is linked to the company's resource planning system in order to not only assess the sustainability performance of each company's as-is operations, but also optimise their future performance. An Australian company was used as a case study to demonstrate the validity of the tool.
TL;DR: In this paper, the authors present equipment for testing asperity deformation at various normal loads and subsurface elongations in a metal forming process and show that real contact area ratios increase heavily with increasing subsural expansion due to lowered yield pressure on the asperities when imposing normal stress parallel to the surface.
Abstract: New equipment for testing asperity deformation at various normal loads and subsurface elongations is presented. Resulting real contact area ratios increase heavily with increasing subsurface expansion due to lowered yield pressure on the asperities when imposing subsurface normal stress parallel to the surface. Finite element modelling supports the presentation and contributes by extrapolation of results to complete the mapping of contact area as function of normal pressure and one-directional subsurface strain parallel to the surface. Improved modelling of the real contact area is the basis for estimating friction in the numerical modelling of metal forming processes.
TL;DR: An international comparison of optical instruments measuring polymer surfaces with arithmetic mean height values in the sub-micrometre range has been carried out in this paper, which involved sixteen optical surface texture instruments (focus variation instruments, confocal microscopes and coherent scanning interferometers).
Abstract: An international comparison of optical instruments measuring polymer surfaces with arithmetic mean height values in the sub-micrometre range has been carried out. The comparison involved sixteen optical surface texture instruments (focus variation instruments, confocal microscopes and coherent scanning interferometers) from thirteen research laboratories worldwide. Results demonstrated that: (i) Agreement among different instruments could be achieved to a limited extent; (ii) standardised guidelines for uncertainty evaluation of areal surface parameters are needed for users; (iii) it is essential that the performance characteristics (and especially the spatial frequency response) of an instrument is understood prior to a measurement.
TL;DR: In this article, a methodology for the design and reconfiguration management of modular assembly systems is proposed, which addresses the selection of the technological modules, their integration in the assembly cell, and the re-configuration policies to handle volume and lot size variability.
Abstract: Automotive suppliers are facing the challenge of continuously adapting their production targets to variable demand requirements due to the frequent introduction of new model variants, materials and assembly technologies. In this context, the profitable management of the product, process and system co-evolution is of paramount importance for the company competitiveness. In this paper, a methodology for the design and reconfiguration management of modular assembly systems is proposed. It addresses the selection of the technological modules, their integration in the assembly cell, and the reconfiguration policies to handle volume and lot size variability. The results are demonstrated in a real automotive case study.
TL;DR: In this paper, a detailed analysis was carried out to correlate the key surface properties to the process parameters so as to determine the optimum conditions, which can optimise the coating performance with deposition.
Abstract: Cold Spray (CS) of copper particles onto polymers has been validated as an effective tool for maintaining surface integrity in bioenvironments. CS requires limited heat input, can be applied locally or in large areas. The key parameters are particle penetration depth and copper surface coverage. However, the process parameters that can optimise the coating performance with deposition have not been comprehensively explored. In this paper, copper particles were deposited onto two polymers used in marine applications. A detailed analysis was carried out to correlate the key surface properties to the process parameters so as to determine the optimum conditions.
TL;DR: In this paper, the authors find and analyse ways of integrating different trades in design workshops aimed at the long-term strategic planning the investment in approaches to integrating design, manufacturing, and procurement departments for leveraging Industry 4.0 potentials.
Abstract: In Industry 4.0, manufacturing technology has a huge potential of becoming a key facilitator for ground-breaking innovations of products, services, and processes. To exploit this potential, industrial organisations have to transform legacy structures and processes in integrated organisations uniting experts from design, manufacturing, procurement, etc. This research accompanies one of the biggest automotive tier-1 supplier along this transformation. The key objective is to find and analyse ways of integrating different trades in design workshops aimed at the long-term strategic planning the investment in approaches to integrating design, manufacturing, and procurement departments for leveraging Industry 4.0 potentials.
TL;DR: In this paper, the authors clarified the mechanism of undesirable vibration observed during high-efficiency elliptical vibration cutting by analyzing the finished surfaces and the undesirable vibrations superimposed on the elliptical vibrations.
Abstract: This research clarifies the mechanism of undesirable vibration observed during high-efficiency elliptical vibration cutting. Elliptical vibration cutting has recently been utilized in practice, and some applications require high-efficiency machining at large width of cut causing vibration problems. Therefore, its mechanism is investigated by analyzing the finished surfaces and the undesirable vibrations superimposed on the elliptical vibration. The vibration is clarified as a kind of frictional chatter induced by ploughing on the tool flank at the beginning of cutting in elliptical vibration cycles and has unique characteristics such as occurrence with sharp tools, low amplitude, and surface waviness at beat frequency.
TL;DR: Results help identify the application with the largest reduction in environmental burden and show that the fibre/matrix combination with the lowest environmental burden also has the best mechanical properties.
Abstract: Natural fibre composites (NFC) are gaining interest in manufacturing because they address some of the environmental problems of traditional composites: use of non-renewable resources, and large impacts related to their production and disposal. Since natural fibres are not yet optimized for composite production, it is crucial to identify the most appropriate applications, and determine the optimal fibre/matrix ratio. A methodology is proposed for early-stage decisions support on selection of bio-composite materials. Results help identify the application with the largest reduction in environmental burden and show that the fibre/matrix combination with the lowest environmental burden also has the best mechanical properties.
TL;DR: The approach aims at directly exploiting redundancy to optimize a given performance measure, e.g., cycle time, through re-parametrization of the trajectory warrants compliance with the robot's kinematic constraints.
Abstract: The paper presents a model and solution method for optimized robot joint motion planning of redundant industrial robots that execute a set of tasks in a complex work environment, in face of various technological and geometric constraints. The approach aims at directly exploiting redundancy to optimize a given performance measure, e.g., cycle time. Alternative configurations along the path are captured in a graph model, whereas bi-directional transition between task and configuration spaces facilitates generating relevant, collision-free configurations only. Re-parametrization of the trajectory warrants compliance with the robot's kinematic constraints. Successful application of the method is demonstrated in remote laser welding.
TL;DR: A systematic approach to reduce epistemic uncertainty in design process in early stages of design is proposed based on “CTOC” and “CPM” to decompose the system behaviour and determine the relationships between function and structure of a system.
Abstract: Integrated product design and development in today's highly competitive and economically challenging world is a complex process depending upon client requirements. One of the main factors contributing to the complexity of process is uncertainty due to lack of system knowledge, known as epistemic uncertainty. This paper proposes a systematic approach to reduce epistemic uncertainty in design process in early stages of design. The approach is based on “CTOC” and “CPM” to decompose the system behaviour and determine the relationships between function and structure of a system. An application of the approach is demonstrated through an industrial case study.
TL;DR: In this paper, a deburring method called abrasive deburring is proposed to remove micro burrs formed at intersecting holes with an appropriate pump pressure, which is not as high as that in the water-jet or extrude-hone method.
Abstract: As industrial technology advances functionally, there is an increasing necessity to treat edges of products well to satisfy the required function. Specifically, burrs inside products at intersecting holes are very difficult to remove because the accessibility of the burr location inside the product to tools is very limited. We propose a new deburring method called abrasive deburring. This method uses a pipe with a hole as a deburring tool to move water with an abrasive and a pump for suction. To determine the suitability of the proposed deburring method, abrasives with different sizes and specific gravities are used. The geometry of the tool and the operating conditions were specified using the following parameters: the diameter of the crossing hole, the diameter of the suction tool, the gap between the sample hole and the tool, the pressure of the pump, and the location of the hole of the tool. The suction-deburring method was very useful for removing micro burrs formed at intersecting holes with an appropriate pump pressure, which is not as high as that in the water-jet or extrude-hone method. However, given the limited deburring force, the method is only applicable for removing micro burrs; other burrs are reduced to stable burrs, which do not require removal from the product.
TL;DR: In this article, an analytical approach to determine the set of relevant KPIs for specific production lines, allowing for a transparent and complete performance measurement, is presented, and a significant reduction of the number of KPIs used could be realized.
Abstract: Key Performance Indicators (KPIs) are frequently used for measuring a production systems’ performance. The selection of KPIs should lead to a set being as small as possible but taking into account all relevant aspects of the system. This paper provides an analytical approach to determine the set of relevant KPIs for specific production lines, allowing for a transparent and complete performance measurement. An LP was formulated for the proposed KPI model and a significant reduction of the number of KPIs used could be realized. The analytical model was tested in a real industrial application.
TL;DR: In this article, an extension of a design process meta-model is proposed to trace the project design memory, instead of seeking past information, industries can look forward innovation and manage changes coming from new technologies, resources, KPI.
Abstract: As the metaphor of a film, engineering design is a process where stakeholders take decisions from product requirements to the final designed system. Unfortunately, industries lack of long term project memories to go back and forth in order to remember actions and decisions. That generates time consuming retrieval tasks that have definitively no added value since they aim at seeking past information. This paper proposes an extension of a design process meta-model that aims at tracing the project design memory. Instead of seeking past information, industries can look forward innovation and manage changes coming from new technologies, resources, KPI...