Showing papers in "Cirp Annals-manufacturing Technology in 2014"

Industrial applications of computed tomography

Abstract: The number of industrial applications of Computed Tomography (CT) is large and rapidly increasing. After a brief market overview, the paper gives a survey of state of the art and upcoming CT technologies, covering types of CT systems, scanning capabilities, and technological advances. The paper contains a survey of application examples from the manufacturing industry as well as from other industries, e.g., electrical and electronic devices, inhomogeneous materials, and from the food industry. Challenges as well as major national and international coordinated activities in the field of industrial CT are also presented.

Turbomachinery component manufacture by application of electrochemical, electro-physical and photonic processes

Abstract: This paper presents an overview of the current technological and economical capabilities of electrochemical (ECM-based), electro-physical (EDM-based) and photonic (Laser-/EBM-based) additive and removal processes for turbomachinery component manufacture. Starting with the industrial demands and challenges of today, the technologies are reviewed in detail regarding achievable geometrical precision and surface integrity as well as material removal and deposition rates for conventionally difficult-to-cut Ti- and Ni-based alloys and dedicated steels. Past, existing and future areas of technology application of these advanced non-mechanical manufacturing processes are discussed. The paper focusses on the description of shaping processes therefore excludes pure welding or coating applications.

Design and management of manufacturing systems for production quality

Abstract: Manufacturing companies are continuously facing the challenge of operating their manufacturing processes and systems in order to deliver the required production rates of high quality products, while minimizing the use of resources. Production quality is proposed in this paper as a new paradigm aiming at going beyond traditional six-sigma approaches. This new paradigm is extremely relevant in technology intensive and emerging strategic manufacturing sectors, such as aeronautics, automotive, energy, medical technology, micro-manufacturing, electronics and mechatronics. Traditional six-sigma techniques show strong limitations in highly changeable production contexts, characterized by small batch productions, customized, or even one-of-a-kind products, and in-line product inspections. Innovative and integrated quality, production logistics and maintenance design, management and control methods as well as advanced technological enablers have a key role to achieve the overall production quality goal. This paper revises problems, methods and tools to support this paradigm and highlights the main challenges and opportunities for manufacturing industries in this context.

Testing and modelling of material behaviour and formability in sheet metal forming

Abstract: The paper deals with the testing and modelling of metals response when subjected to sheet forming operations. The focus is both on the modelling of hardening behaviour and yield criteria and on the description of the sheet metal formability limits. Within this scope, the paper provides a critical review of the models available today for predicting the material behaviour at both industrial and scientific level, and the tests needed to identify the models’ material parameters. The most recent advances in the field are also presented and discussed with particular emphasis on the challenges the sheet metal forming community is now facing.

Grasping devices and methods in automated production processes

Abstract: In automated production processes grasping devices and methods play a crucial role in the handling of many parts, components and products. This keynote paper starts with a classification of grasping phases, describes how different principles are adopted at different scales in different applications and continues explaining different releasing strategies and principles. Then the paper classifies the numerous sensors used to monitor the effectiveness of grasping (part presence, exchanged force, stick-slip transitions, etc.). Later the grasping and releasing problems in different fields (from mechanical assembly to disassembly, from aerospace to food industry, from textile to logistics) are discussed. Finally, the most recent research is reviewed in order to introduce the new trends in grasping. They provide an outlook on the future of both grippers and robotic hands in automated production processes.

A cloud-based approach for WEEE remanufacturing

Abstract: The modern manufacturing industry calls for a new generation of integration models that are more interoperable, intelligent, adaptable and distributed. Evolved from service-oriented architecture, web-based manufacturing and cloud computing, cloud manufacturing is considered worldwide a new enabling technology for manufacturing enterprises to respond quickly and effectively to the changing global market. For Waste Electrical and Electronic Equipment (WEEE) in particular, it is a critical necessity to recycle, reuse and remanufacture WEEE products by setting up a cloud-based information system. In this paper, a novel service-oriented remanufacturing platform is proposed based on the cloud manufacturing concept.

Tools and techniques for product design

Abstract: For product designers, tools and techniques are essential in driving the design cycle. Nevertheless, their employment usually is implicit, while passing over e.g. the design and project environments empowering their adequate use. This publication presents an overview of approaches in structuring and using tools/techniques, based on the effectuation of creativity and decision-making in the design environment. In elaborating on characteristics of tools/techniques and ensuing ways of selecting them, the designer's portfolio of tools/techniques is characterised. Representative problems of tool/technique usage are depicted and contextualised by illustrating their industrial application. Prospects for future developments are also reviewed

Generation of hierarchical micro-structures for anisotropic wetting by elliptical vibration cutting

Abstract: This paper reports enhanced anisotropic wettability using two-level hierarchical micro-structures. First-order micro-channels with superimposed second-order micro-textures were machined on aluminum surfaces using ultrasonic elliptical vibration cutting (EVC). Controllable sinusoidal micro-textures with a wavelength one order of magnitude smaller than the widths of the first-order micro-channels were applied to the surface. Anisotropic wettability was evaluated by water contact angle measurements in two orthogonal directions. The results have shown that the generated hierarchical micro-structures have nearly doubled the anisotropic contact angle in comparison to one-level structures. A relationship between anisotropic wetting characteristics and process parameters is also presented.

Dealing with uncertainty in disassembly line design

Abstract: A disassembly process is usually characterized by a high level of uncertainty due to the quality of End-of-Life products. This paper presents an efficient approach for designing disassembly lines with the objective to maximize the line profit. Task times are assumed to be random variables with known probability distributions. An AND/OR graph is used to model the precedence relationships among tasks and subassemblies and the disassembly alternatives. A Monte Carlo sampling based exact solution method is developed to deal with uncertainties. Results of experiments on problem instances are presented.

Cylindrical milling tools: Comparative real case study for process stability

Abstract: Critical comparison is presented related to the stability behaviour of milling processes performed by conventional, variable helix and serrated milling tools. The paper presents a general milling model linked to any non-proportionally damped dynamic system. Extended multi frequency solution and semi-discretization are implemented and used to calculate the stability of stationary milling. Measurements performed in industrial environment validate the general numerical algorithm that is able to predict the stability conditions of milling processes carried out by cylindrical cutters of optional geometry. Both the calculations and the measurements confirm that, for roughing operations, the highest stability gain can be achieved by serrated cutters. It is also demonstrated that variable helix milling tools can achieve better stability behaviour only if their geometry is optimized for the given cutting operation.

Capacity management for assembly systems with dedicated and reconfigurable resources

Abstract: Managing changes and disturbances resulted by fluctuating order streams and diverse product portfolios requires efficient capacity management decisions and production planning strategies. High volume products can be produced cost efficiently on dedicated assembly lines, while the assembly of low runners is more efficient on reconfigurable lines. In the paper a hierarchical planning decision workflow is introduced to assign the products to dedicated and reconfigurable lines, and to optimize the system configuration and the production plan of the reconfigurable system in an integrated way. The proposed solution is demonstrated through the results of an industrial case study. © 2014 CIRP.

Optimization of the plasma oxidation and abrasive polishing processes in plasma-assisted polishing for highly effective planarization of 4H-SiC

Abstract: For the finishing of difficult-to-machine materials, plasma-assisted polishing (PAP), which combines modification by water vapor plasma and polishing by a soft abrasive, was proposed. Optimization of plasma oxidation and abrasive polishing was conducted to increase the material removal rate of PAP, which was applied to 4H-SiC (0 0 0 1). It was found that with a low concentration of water vapor in helium gas, the plasma oxidation rate was greatly increased. Also, because of the different oxidation rates of the four types of terrace that appear alternately in 4H-SiC, a high removal rate of the oxide was necessary to obtain a uniform step–terrace structure with atomic order.

Characterization of electrically-assisted micro-rolling for surface texturing using embedded sensor

Abstract: Electrically-assisted micro-rolling (EAμR) takes advantage of localized heating by loading current through the deformation zone to enhance the texturing capability of Ti-6Al-4V and AA3003-H14. The challenge to achieve a desired deformation pattern is the lack of reliable models to capture the often non-uniform mechanical and thermal behaviors. In this paper, pressure distributions are measured by a custom-designed, tool-embedded sensor. Furthermore, the effects of current on texturing are first characterized using a coupled mechanical and thermal model. Comparison between modeling and experimental results confirmed the effectiveness of EAμR on texturing and the importance of multi-physics modeling.

The implications of automobile parts supply network structures: A complex network approach

Abstract: This study investigates the temporal structural transitions of automobile supply networks where, under situations with various possible risks such as economic crises and market globalisation, companies must both work together for sustainable production, and also compete with each other for their own survival. The resulting network complexity is captured by large-scale empirical data, and analysed for the first time using concepts and metrics developed in complex network science. We discuss how network structure reflects the effect of several factors including market fluctuation, product standardisation, technological advancement, and financial interdependencies between companies.

Adapting CAD models of complex engineering objects to measured point cloud data

Abstract: Construction, maintenance and retrofitting of complex engineering objects like factories or plants calls for matching their model and actual state that are inevitably different. The paper presents a generic method for tailoring the computer aided design (CAD) model of such objects to their state given in terms of measured 3D, high resolution point clouds. The workflow includes efficient storage of massive measurement data, segmentation of a triangulated mesh-based CAD model into features, matching and adapting the features to the data. The method is demonstrated in a real-world setting, using the CAD model and point cloud data of an industrial plant.

Laser surface hardening of large cylindrical components utilizing ring spot geometry

Abstract: A new process, based on ring spot geometry, is presented for laser surface hardening of large cylindrical components. The proposed technique leads to a very hard, deep and uniform hardened layer along the entire work piece surface without introducing a tempered zone, making the process very attractive compared to conventional induction hardening that exhibits both low energy efficiency and poor flexibility. A complete physical model is presented for the process, together with a study of the influence of process parameters on the final outcome. The results of an extensive validation campaign, carried out on AISI 1040 specimens, are also reported.

Automated in-service damage identification

Abstract: Service damage for mechanical components includes surface delamination, impact damage, crack, wear and corrosion. Automated service damage identification for better analysis of a component remaining life in order to reduce the service cost is increasingly necessary for industrial product-service systems, e.g. power-by-hour contracts. This paper presents a novel approach to apply active thermography and image processing techniques for damage identification and measurement. The study presents experimental results to assess the shape, size and depth of sub-surface damage features on test and real life components. Industrial requirements for the non-destructive inspection for a class of aerospace components are also presented.

Analytical prediction of contact stiffness and friction damping in bolted connection

Abstract: This paper presents an analytical method to predict contact stiffness and friction damping in bolted connections. Despite its importance in machine design, analytical prediction of the contact parameters has not been realized because of difficulty in time-history nonlinear analysis of sticking/sliding contact. In this study, a torsional contact model around a connecting bolt is developed. Linear phenomena are extracted and solved by FEM analysis, and then linear combination of the FEM results is calculated iteratively to search sticking/sliding zones in torque equilibrium. Proposed model is experimentally validated, and it will lead to fully analytical modelling of practical machines.

Proposal of "open-loop" tracking interferometer for machine tool volumetric error measurement

Abstract: The tracking interferometer, or the laser tracker, is a laser interferometer with a mechanism to control the laser beam direction to follow a retroreflector (“target”). Applying the multilateration principle, the target's three-dimensional position is measured. This paper proposes a novel concept of “open-loop” tracking interferometer, where the laser beam is controlled towards the command target position. Its advantage is in the elimination of the automated tracking mechanism, which may significantly reduce its manufacturing cost. The paper's emphasis is on analytical evaluation of its measurement uncertainty, introduced by the elimination of automated tracking mechanism. A prototype “open-loop” tracking interferometer is developed, and its measuring performance is experimentally investigated.

Network based requirement specification

Abstract: Requirement specifications often resemble static design briefs Whereas such unequivocal references are essential, the dynamics of product development require more insight, nuancing, flexibility and evolvement This encompasses relative importance, context and provenance of the requirements related to the different stakeholders involved In developing responsive requirement specifications, the so-called actor network is employed Such a network maps the relevant stakeholders over the development life cycle, thus expressing the set of requirements as a whole, as well as the evolving coherence between them This publication demonstrates the structure and purpose of network based requirements and the added value for product developers

Characterization of precision of a handling system in high performance transfer press for micro forming

Abstract: Multi-step micro bulk forming is characterized by complex processes and high precision requirements. In particular the demands regarding handling accuracy between different forming steps are of the order of a few μm. The paper introduces a methodology for the analysis and characterization of this transfer system on component level and system level. Laser interferometry is used in combination with analytical models to predict the positioning ability of the actuator in a static as well as dynamic mode. In combination with an analysis of the grippers, a full description of the transfer precision inside the forming press is obtained.

An Innovative Experimental Study of Corner Radius Effect on Cutting Forces

Abstract: The cutting forces are often modelled using edge discretisation methodology. In finish turning, due to the smaller corner radii, the use of a local cutting force model identified from orthogonal cutting tests poses a significant challenge. In this paper, the local effect of the corner radius rɛ on the forces is investigated using a new experimental configuration: corner cutting tests involving the tool nose. The results are compared with inverse identifications based on cylindrical turning tests and elementary cutting tests on tubes. The results obtained from these methods consistently show the significant influence of the corner radius rɛ on the cutting forces.

Modelling and analysis of uncertainty in the form characterization of ultra-precision freeform surfaces on coordinate measuring machines

Abstract: This paper presents an uncertainty analysis model for the form characterization of ultra-precision freeform surfaces on coordinate measuring machines (CMM). The model is developed by incorporating the effect of the CMM, the sampling plan, and the evaluation method taking into account workpiece form deviations. It allows the analysis of the uncertainty of evaluated surface parameters with respect to the magnitude of the workpiece form deviation based on Monte Carlo simulation. The effectiveness of the model was successfully verified using a designed freeform artefact on a precision CMM. The model should make the reliable form characterization of ultra-precision freeform surfaces possible.

Dynamic modelling of impact of lean policies on production levelling feasibility

Abstract: A dynamic systems approach is proposed to investigate challenges of implementing production levelling and associated costs. A model of a lean cell is developed using system dynamics. The model captures various lean tools influencing production levelling. Comparative cost analysis between various levelling implementation policies for stochastic demand with multiple products is conducted. Results showed that determining the most feasible levelling policy is highly dictated by both capacity scalability cost and limitations. The developed model and revealed insights can help lean practitioners to better decide on when and how to implement production levelling as well as determine production lots sizes.

Method to explore technology innovation fully exploitin in-house capabilities

Abstract: This paper proposes a design method to seek potential product innovation fully exploiting in-house capabilities. The method triggers scientists, designers and engineers in discovering both new instantiations of physical principles and new physical phenomena that may appear by modifying the embodiment of existing technologies. The embodiment modifications are constrained by the in-house manufacturing techniques to seek innovative solutions without the burden of heavy capital investments. The newly discovered principles and phenomena are tested for possible affordances leading to new product functions. The design method is applied in an industrial technology exploration and led to the discovery of two new technologies