Showing papers in "Cirp Annals-manufacturing Technology in 2013"
TL;DR: In this paper, the authors discuss the challenges of managing product variety throughout the entire product life cycle, and the effective co-development of variants and their manufacturing systems to ensure economic sustainability.
Abstract: A great challenge facing industry today is managing variety throughout the entire products life cycle. Drivers of products variety, its benefits, pre-requisites and associated complexity and cost are presented. Enhancing consumers’ value through variety and approaches for achieving it efficiently including modularity, commonality and differentiation are discussed. Variant-oriented manufacturing systems paradigms, as enablers of product variety, and the effective co-development of variants and their manufacturing systems to ensure economic sustainability are reviewed. Industrial applications and guidelines to achieve economy of scope with advantages of economy of scale are discussed. Perspectives and insights on future research in this field are offered.
536 citations
TL;DR: In this article, a review of the models that have been developed to simulate each of these phenomena, e.g. potential models to calculate the current density distribution in ECM, thermal models for the plasma arc in EDM, moving boundary models to simulate the anodic dissolution in the ECM and probabilistic models to determine the discharge location in the EDM.
Abstract: The modelling of ECM and EDM processes requires not one but several models to simulate the different phenomena that occur during machining. This paper reviews the models that have been developed to simulate each of these phenomena, e.g. potential models to calculate the current density distribution in ECM, thermal models for the plasma arc in EDM, moving boundary models to simulate the anodic dissolution in ECM and probabilistic models to determine the discharge location in EDM. In addition to discussing the relative merits of the techniques deployed in these models, the paper describes some salient applications and concludes with desirable future enhancements to these models.
203 citations
TL;DR: A critical review of such inspiring biological surfaces and their nonbiological product analogs can be found in this article, where manufacturing science and engineering have adopted such advanced functional surface architectures.
Abstract: Over millions of years, biological subjects have been in continuous combat with extreme environmental conditions. The fittest have survived through continuous evolution, an ongoing process. In particular, biological surfaces, which are the active interfaces between subjects and the environment, are being evolved to a higher state of intelligent functionality. These surfaces became more efficient by using combinations of available materials, along with unique physical and chemical strategies. Noteworthy physical strategies include features such as texturing and structure, and chemical strategies such as sensing and actuation. These strategies collectively enable functional surfaces to deliver extraordinary adhesion, hydrophobicity, multispectral response, energy scavenging, thermal regulation, antibiofouling, and other advanced functions. Production industries have been intrigued with such biological surface strategies in order to learn clever surface architectures and implement those architectures to impart advanced functionalities into manufactured consumer products. This keynote paper delivers a critical review of such inspiring biological surfaces and their nonbiological product analogs, where manufacturing science and engineering have adopted such advanced functional surface architectures.
199 citations
TL;DR: An approach for incorporating both lean and green strategies into a manufacturing system; from data collection to the valuation of a system is presented, and a case study is presented of part production in the automotive sector, in which the implementation of a tailored combination of lean andGreen strategies resulted in the reduction of approximately 10.8% of the production costs of a representative part.
Abstract: CIRP Annals - Manufacturing Technology 62 (2013) 475–478 Contents lists available at SciVerse ScienceDirect CIRP Annals - Manufacturing Technology jou rnal homep age : ht t p: // ees .e lse vi er . com /ci r p/ def a ult . asp Assessment of lean and green strategies by simulation of manufacturing systems in discrete production environments Nancy Diaz-Elsayed a, *, Annabel Jondral b , Sebastian Greinacher b , David Dornfeld (1) a , Gisela Lanza (2) b a b Laboratory for Manufacturing and Sustainability, University of California, Berkeley, USA Institute for Production Science, Karlsruhe Institute of Technology, Karlsruhe, Germany A R T I C L E I N F O A B S T R A C T Keywords: Production planning Simulation Sustainable development Manufacturing is a resource-intensive and costly endeavor, yet the impacts of implementing a combination of lean and green practices in a manufacturing facility can hardly be forecasted and have typically been simulated, optimized, and valuated independently. This paper identifies an approach for incorporating both lean and green strategies into a manufacturing system; from data collection to the valuation of a system. Furthermore, a case study is presented of part production in the automotive sector, in which the implementation of a tailored combination of lean and green strategies resulted in the reduction of approximately 10.8% of the production costs of a representative part. s 2013 CIRP. 1. Motivation The cost of energy and resources are constantly increasing due to rising demand and limited supply. Furthermore, price trends can hardly be forecasted, so companies aim to successfully produce within large price ranges of energy and resources. One strategy to accommodate price fluctuations consists of passing markups to the customer. However, a price markup may require that improve- ments be made to the product. Alternatively, stable prices may be facilitated with increased production efficiency, which can be achieved by reducing resource consumption and improving the organization of the manufacturing system. This paper focuses on the latter strategy and presents an approach for the assessment of lean and green strategies by simulation of manufacturing systems. The optimal combination of strategies depends on the industry and relevant processes. For instance, the effects of reducing batch size and solvent consump- tion differs between a paint shop and an assembly line in the automotive industry. Therefore, solutions must be tailored to accommodate specific applications in order to maximize impact. scheduling [9–11] and additional process planning [12,13] techniques on factory level energy consumption. Herrmann et al. developed a simulation to analyze the effects of implementing lean and green manufacturing strategies on energy consumption and costs [14]. Extensive research has been conducted in the fields of ‘‘simulating and optimizing’’ or ‘‘simulating and valuating’’ the application of lean and/or green strategies in manufacturing systems. However, the literature lacks an assessment methodology capable of simulating, optimizing, and valuating a manufacturing system’s performance indicators while using a tailored combina- tion of lean and green strategies. Such an assessment methodology would allow companies to evaluate the effectiveness of strategies before spending funds to implement them on the shop floor. 3. Assessment of lean and green strategies by simulation The following section describes an assessment methodology for simulating, optimizing, and valuating a manufacturing system’s performance indicators while using a tailored combination of lean and green strategies. 2. Literature review 3.1. Modeling the current state This literature review focuses on simulation-based approaches, a special case of quantitative assessment. A variety of approaches have been constructed to simulate the effects of applying lean methods in manufacturing, i.e., illustrating differences between a real and ideal state [1], examining their impact on performance indicators [2–4], and bundling simulation results in Cost-time profiles [5,6]. Research in green manufacturing spans a variety of scopes within the factory, from the development of energy models of production equipment [7,8] to the assessment of machine * Corresponding author. 0007-8506/$ – see front matter s 2013 CIRP. http://dx.doi.org/10.1016/j.cirp.2013.03.066 In order to set up a simulation model of a manufacturing system and subsequently optimize it, a variety of data needs to be gathered. The required data for each product variant that is manufactured can be categorized into factory and operational data, energy and resource requirements, and employee involvement. All data needed to set up the discrete event simulation model of the current state can be measured on the shop floor or estimated with historical data. In order to create a simulation model capable of valuating the increase in a production system’s performance, installing multiple levels and building reusable modules is recommended. In a typical discrete production environment, one
133 citations
TL;DR: In this article, the surface temperature on metal powder during the laser consolidation process with two-color pyrometer was measured with high speed video camera and the results showed that the metal powder at the heating process cohered intermittently to the melt pool although the laser beam was continuously irradiated to the powder surface.
Abstract: This paper deals with the measurement of surface temperature on metal powder during the laser consolidation process with two-color pyrometer. Additionally, the aspect of selective laser sintering (SLS) and selective laser melting (SLM) of metal powder is visualized with high speed video camera. As a result, the surface temperature during the laser irradiation was ranged 1520–1810 °C and the consolidation phenomena was classified according to the melting point of metal powder. The metal powder at the heating process cohered intermittently to the melt pool although the laser beam was continuously irradiated to the powder surface.
100 citations
TL;DR: In this article, the feasibility of producing sheet components by stamping AA5083 sheets at elevated temperature and strain rate was evaluated by using tensile and Nakajima-type tests to determine the optimal combination of process parameters assuring both maximum formability and effective post deformation mechanical properties.
Abstract: The paper is aimed at proving the feasibility of producing sheet components by stamping AA5083 sheets at elevated temperature and strain rate. Laboratory tensile and Nakajima-type tests were carried out to evaluate the material flow stress, ductility and fracture limits sensitivity to temperature and strain rate, and therefore to determine the optimal combination of process parameters assuring both maximum formability and effective post-deformation mechanical properties. Industrial trials were conducted on an automotive component to validate the laboratory results.
94 citations
TL;DR: In this article, the authors present an overview of research on sustainability of abrasive processes, which includes environmental, social, and economic sustainability in accordance with the definition proposed in the Brundtland Report of the United Nations.
Abstract: This paper presents an overview of research on sustainability of abrasive processes. It incorporates results from a round robin study on “energy-efficiency of abrasive processes” which has been carried out within the scientific technical committee “abrasive processes” (STC G) of CIRP, the content of technical presentations in STC G, and the results of a comprehensive literature study. The approach to sustainability includes environmental, social, and economic sustainability in accordance with the definition proposed in the Brundtland Report of the United Nations [156] . The main focus is on environmental and social sustainability. Economic sustainability will be considered as manufacturing productivity.
89 citations
TL;DR: Hierarchical clustering (cladistics) is proposed to automatically build product hierarchical architecture from DSM because DSM is a flat connectivity map that does not capture the layered nature of the product structure.
Abstract: In modular architectures, Design Structure Matrix (DSM) is used to cluster product components into modules with minimum interfaces externally and maximum internal integration between components. However, DSM is a flat connectivity map that does not capture the layered nature of the product structure. Hierarchical clustering (cladistics) is proposed to automatically build product hierarchical architecture from DSM. The resulting clustering tree represents product architecture while its depth represents its granularity. The optimum granularity level and number of modules are determined, indicating the potential product and process platforms. A case study of automobile body-in-white of 38 components is used to demonstrate the capabilities and superior results quality of the presented technique.
75 citations
TL;DR: In this article, a conceptual framework for CT measurement uncertainty based on the ISO-GUM, starting from the product of the voxel size and the number of voxels as the description of every CT measurement, is presented.
Abstract: With the introduction of computed tomography (CT) for purpose of dimensional quality control, the problem has arisen of identifying the measurement uncertainty of CT-based length measurements. This paper presents a conceptual framework for CT measurement uncertainty based on the ISO-GUM, starting from the product of the voxel size and the number of voxels as the description of every CT measurement. Those two main uncertainty contributors are further subdivided and illustrated based on various measurements. Finally, this paper shows how a measurement procedure, based on voxel size and edge correction can eliminate some terms of the total uncertainty budget.
66 citations
TL;DR: In this paper, a mechanistic force model for double helix tools is developed based on milling force data obtained on flat end mills, which can be used to improve double-helix tool designs and to optimize milling process parameters.
Abstract: Carbon fiber reinforced polymers (CFRP) have emerged as the material of choice to satisfy increasing demand for lighter aircrafts. Machinability characteristics of CFRPs are quite different than those of metals; therefore, special tool designs have been developed for CFRP machining. The double helix end mill design compresses the upper and lower sides of the laminate using opposite helix angles that eliminate delamination. A mechanistic force model for double helix tools is developed based on milling force data obtained on flat end mills. The proposed model can be used to improve double helix tool designs and to optimize milling process parameters.
60 citations
TL;DR: In this paper, a comparative analysis of boundary conditions in Belgium and Japan that cause the adoption of diverse treatment strategies for the rapidly increasing number of end-of-life flat screen TVs is presented.
Abstract: Differences in legislation and markets for recycled materials result in the national implementation of distinct end-of-life treatment strategies. This paper presents a comparative analysis of the boundary conditions in Belgium and Japan that cause the adoption of diverse treatment strategies for the rapidly increasing number of end-of-life flat screen TVs. In addition, both treatment strategies are evaluated from an ecological and economic perspective and opportunities for improvement are identified.
TL;DR: A model to integrate the traditional requirements process into Axiomatic Design Theory and proposes a method to structure the requirements process that includes a requirements classification system, a stakeholder classification system to reduce the chances of excluding one or more key stakeholders, and a table to visualize the mapping between the stakeholders and their requirements.
Abstract: This paper introduces a model to integrate the traditional requirements process into Axiomatic Design Theory and proposes a method to structure the requirements process. The method includes a requirements classification system to ensure that all requirements information can be included in the Axiomatic Design process, a stakeholder classification system to reduce the chances of excluding one or more key stakeholders, and a table to visualize the mapping between the stakeholders and their requirements.
TL;DR: In this paper, a laser-induced plasma micro-machining (LIPMM) process was proposed, in which plasma induced in a liquid at the focal point of the laser beam is used to perform micro machining.
Abstract: This paper presents a new micro-machining process, laser-induced plasma micro-machining (LIPMM), in which plasma induced in a liquid at the focal point of the laser beam is used to perform micro-machining. It is shown that LIPMM can machine a variety of materials including metal alloys, polymers and ceramics. A process variant, line-LIPMM (L-LIPMM), based on optical manipulation of the laser beam to create line- instead of spot-plasma, is developed. Additionally, a second variant, magnetically-controlled LIPMM (MC-LIPMM), in which an external magnetic field is used to manipulate the shape of the plasma, is developed to further increase process throughput and flexibility.
TL;DR: In this article, a methodology based on the sensorless force control technique and the quarry matrix capable of the mode decoupling is proposed for a parallel mechanism polishing machine to control x-y trajectory, tool posture, and polishing force in z-direction, and its validity for automated buffing is verified.
Abstract: The buffing process for finishing an automobile's body is still done manually, and the final surface quality of the body depends on the skill and technique of the worker. To automate buffing, not only tool path control but also precise and fast force control is required. In this study, a novel methodology based on the sensor-less force control technique and the quarry matrix capable of the mode decoupling is proposed for a parallel mechanism polishing machine to control x–y trajectory, tool posture, and polishing force in z-direction, and its validity for automated buffing is verified.
TL;DR: In this article, the relationship among process conditions, surface integrity, and fatigue in dry milling of hardened H13 steel was investigated, showing that superior surface integrity including good surface finish, highly compressive residual stress, free-of white layer, and work-hardening can be produced up to flank wear at least 0.2mm.
Abstract: Dry milling is a sustainable finishing process in mold/die manufacturing. However, the progression of tool wear causes great concern on inferior surface integrity and reduced part life. This study focuses on the relationships among process conditions, surface integrity, and fatigue in dry milling of hardened H13 steel. Superior surface integrity including good surface finish, highly compressive residual stress, free-of white layer, and work-hardening can be produced up to flank wear at least 0.2 mm. Furthermore, fatigue life of the machined surfaces in finish conditions reaches over 1 million cycles under the synergistic effect of high compressive residual stress and work-hardening.
TL;DR: In this article, a non-linear finite element model is used to calculate the geometrical gear meshing positions under operational loads, and these positions are then used as inputs of a calculation process that seeks to define the best tooth surface topography.
Abstract: This paper aims to present the new method developed to generate optimized spiral bevel gear surfaces. Thanks to a complex non linear finite element model, the geometrical gear meshing positions under operational loads are first precisely computed. These meshing positions are then used as inputs of a calculation process that seeks to define the best tooth surface topography. So far, this activity was based on sensitivity studies conducted directly by the designer, which led to repeat calculations whose progress was difficult to control.
EUROCOPTER uses now optimization algorithms to compute automatically the surfaces of the tooth contact flanks. This approach leads to higher performances of the gear while reducing the development time. This paper describes the new process implemented to design the tooth shape, and illustrates its interest through an example.
Journal Article•
TL;DR: In this paper, a novel grasping-releasing strategy exploits the transition between hydrophobic and hydrophilic surfaces to change the grasping force, and demonstrates the use of such structures to grasp and release delicate mini and microparts.
Abstract: In the assembly of microproducts the grasping and releasing phases are key tasks. Since in the microdomain gravity becomes negligible in comparison with adhesion forces, several reliable grasping methods have been developed. On the contrary, the releasing phase is still very critical because the part tends to stick to the gripper. In this paper a novel strategy based on capillary forces both for grasping and releasing is proposed. This novel grasping-releasing strategy exploits the transition between hydrophobic and hydrophilic surfaces to change the grasping force. The paper starts from the releasing problem in microassembly, deals with the manufacturing of hydrophobic and hydrophilic surfaces and demonstrates the use of such structures to grasp and release delicate mini and microparts.
TL;DR: This paper presents an approach to joint optimization problems based on a Stackelberg game to achieve equilibrium solutions that leverage upon multiple conflicting goals of design.
Abstract: Seeking optimal solutions has been one of important tasks in engineering design. Design optimization problems have normally been formulated by aggregating diverse criteria into one single objective function subject to a set of constraints. There is a growing number of engineering systems, however, involving coupling of multiple optimization problems that are competing in nature and yet must simultaneously satisfy various conflicting objectives. Such joint optimization of multiple competing optimization problems is very difficult, if not impossible, to be modelled and solved with traditional multi-objective optimization methods. This paper presents an approach to joint optimization problems based on a Stackelberg game to achieve equilibrium solutions that leverage upon multiple conflicting goals of design.
TL;DR: In this paper, an automated process planning method that departing from the geometric part model and the description of machining resources generates a portfolio of executable process plans with the objective to maximize the throughput of a workshop.
Abstract: Balancing the load in workshops of versatile machines can be significantly improved if parts are processed through alternative routings. The paper presents an automated process planning method that departing from the geometric part model and the description of machining resources generates a portfolio of executable process plans with the objective to maximize the throughput of a workshop. Parts may have rotational, planar and freeform surfaces. A new model is suggested for the macro planning phase where a combination of geometric reasoning and constrained combinatorial optimization generates alternative setups, resource assignments and operation sequences. The method is demonstrated in industrial setting.
TL;DR: A framework integrating the uncertainty propagation through different product characteristics and its effect on product properties is presented, which consists of a descriptive model based on formal logic and characteristics properties model; a mathematical implementation through set theory and probabilistic approach; and an algorithm for design space evaluation and tolerancing.
Abstract: Uncertainty in product characteristics is ubiquitous in any engineering system at all the stages of product life-cycle. Considering uncertainty from different sources during the product design phase is critical to its reliable performance. This paper presents a framework integrating the uncertainty propagation through different product characteristics and its effect on product properties. The framework consists of three main parts: a descriptive model based on formal logic and characteristics properties model; a mathematical implementation through set theory and probabilistic approach; and an algorithm for design space evaluation and tolerancing. The application of framework is demonstrated through an industrial case study.
TL;DR: In this article, the authors propose an approach to ensure that the parameterisation used to build the CAD model reflects the manufacturing capability, ensuring design intent is maintained from concept to manufacture.
Abstract: Design and manufacture of aircraft requires deep multi-disciplinary understanding of system behaviour. The intention of the designer can get lost due to the many changes occurring to the product and the inability of the methods and tools used to capture it. Systems engineering and optimisation tools underpin industrial approaches to design, but are not without issue. The challenge is to find a route from concept to manufacture which enables designers to maintain their original intent. The novelty in this work is that the parameterisation used to build the CAD model reflects the manufacturing capability, ensuring design intent is maintained from concept to manufacture.
TL;DR: In this paper, a flexible version of the helical slide method is used to remove traces of inversions in a linear trajectory with large radii and high cutting speed, which promotes the removal of material thus saving time.
Abstract: The paper discusses a flexible honing technology by describing the new prototype machine with its specificity. Three original methods produced by the flexible honing prototype have been studied. A path combines the two contemporary methods of industrial honing: the helical slide honing at 135° at the bottom of the cylinder and the conventional honing at 45° on the upper part. This method of honing shows the effectiveness of specific motion tracking to remove traces of inversions. Circular trajectories with large radii can be traveled quickly without consuming too much energy. The high cutting speed promotes the removal of material thus saving time. Finally, the multi-circle paths can get original textures thus proving the feasibility of all patterns.
TL;DR: In this paper, a series of SERS Raman spectra suggested that a reacted thin film formed on the copper surface, which was measured using a custom-built measurement system, revealing the role of the copper-fullerenol interaction in the chemical reaction process during Cu-CMP.
Abstract: In Cu-CMP using a fullerenol slurry, effective planarization in terms of high removal rate has been confirmed. The high chemical reactivity of fullerenol is suggested to be an essential factor for copper material removal. In situ surface analysis based on the SERS method was performed to reveal the role of the copper–fullerenol interaction in the chemical reaction process during Cu-CMP. A series of SERS Raman spectra suggested that a reacted thin film formed on the copper surface, which was measured using a custom-built measurement system.
TL;DR: In this article, the reliability of artificial hip joints' surface generated by the electrolytically treated grinding process was evaluated in a hip simulator and animal tests, and the results of animal test showed that the fabricated surface could have a highly improved biocompatibility.
Abstract: The purpose of this paper is to prove the reliability of artificial hip joints’ surface generated by the electrolytically treated grinding process; the evaluation was carried out in a hip simulator and animal tests. The evaluation indicated that the fabricated hyper-hemispherical shaped artificial hip joints presented a high quality smoother surface than 10 nm in Ra. The fabricated surface also showed its ability to prevent crystalline phase transition during the hip simulation test, suggesting that the stably modified layer was generated via grinding process. The results of animal test showed that the fabricated surface could have a highly-improved biocompatibility.
TL;DR: In this paper, the authors present levels of knowledge enrichment for designers (multi-scale experiments and models), analysis of process influence on models improvement, and a discussion for an efficient testing strategy (meaning virtual testing in order to reduce the number of tests and their costs).
Abstract: Hydrogen stock vessels add new product specifications because of higher pressure use. Today static application leads up to 700 bars. But pressure devices must resist, because of certification, at 3 times pressure (2100 bars). Composite vessels give material–structure potential solutions. But designers face limits of knowledge due to actual good practices of thick composite structures use. This paper presents levels of knowledge enrichment for designers (multi-scale experiments and models), analysis of process influence on models improvement, and a discussion for an efficient testing strategy (meaning virtual testing in order to reduce the number of tests and their costs).
TL;DR: In this paper, a 0.64%C steel wires were oxidized at 923 K under air and chemically reduced by pure hydrogen to form a porous surface layer with pores 1-2μm in diameter.
Abstract: As a lubricant for steel cold working, metal soap on zinc phosphate coating is widely used. However the lubrication causes hazardous wastes, and hence an alternative system is demanded. The authors proposed to utilize porous layer on workpiece surface as a reservoir of liquid lubricant. In this study, 0.64%C steel wires were oxidized at 923 K under air and chemically reduced by pure hydrogen to form porous surface layer with pores 1–2 μm in diameter. In cold drawing with machine oil, the friction coefficient on the porous surface was 0.06, while that on normal surface was 0.11. The lubrication mechanism with porous surface is discussed.