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Machining operations such as turning, milling, and drilling are commonly employed machining processes in industry. With the push toward a future of sustainable manufacturing, machining processes need to be evaluated and optimized accordingly. This paper focuses on the energy aspects in metal cutting and attempts to provide an overall assessment of energy consumption and energy efficiency against the operating conditions. Specifically, the effects of tool geometry and cutting parameters in turning of ANSI 4140 steel are investigated through numerical experiments using finite element simulation. The variables considered include cutting speed, rake angle, nose radius, and edge radius. The effects of these parameters on cutting energy consumption and cutting efficiency are analyzed. The results show that the effects of these parameters on cutting energy and cutting efficiency are different. Strategies for minimizing cutting energy and maximizing cutting efficiency are suggested. [ABSTRACT FROM AUTHOR]

Abstract: This study addressed the issue of automated material handling systems (AMHS) in the photolithography zone of a 300mm (12-in.) wafer fab facility. The lithography process accounts for 40–50% of the time required to produce wafers. Therefore, managing the AMHS in the photolithography zone is a challenging task. This paper examines the dispatching rule and the number of vehicles in variable wafer input cases. With a stochastic and complex manufacturing process, a photobay simulation may lead to excessive iterations and wasted computation time. The most frequently used approach for process management in the literature is performance analysis with a model that simulates each alternative for N times. However, this approach becomes time consuming as the number of variables and iterations increases. To address this issue, we use Optimal Computing Budget Allocation (OCBA) and extend OCBA by adding particle swarm optimization (PSO). With this combined approached, the number of iterations of each alternative is determined by OCBA, and the optimal solution in the domain of feasible solutions is identified through PSO. This research provides a useful reference to optimally allocate lithographical resources and the number of iterations with random parameters for both scholars and practitioners. Results demonstrate the superiority of PSOOCBA in terms of searching quality and robustness. [Copyright &y& Elsevier]

Electrodialysis metathesis is an attractive technology to synthesize electrolyte by electrodialysis technology. It could realize the metathesis reaction and product concentration simultaneously in one process. A semi-empirical mathematical model based on Nernst–Planck equations was built to describe the continuous EDM process converting Na 2 SO 4 to K 2 SO 4. The parameters of mathematical model were determined by the experimental data. The simulated results were verified by the laboratory scale test and a pilot-scale experiment. The economic feasibility of an industrial scale process was evaluated. It was indicated that the current density had a significant effect on the capital cost of EDM, while the effect of feed concentration was small. The specific cost of EDM was lowest when the current density was 150 A·m−2 in this paper. [Display omitted] • A semi-empirical model for continuous EDM process was developed and applied to the simulation of industrial process. • The equation of water flux from different dilute solution was determined by the ion hydration numbers. • The capital cost of membrane occupied about 50% of the total ones. • The capital cost was reduced as the current density was increased, and variated little as the concentration was increased. [ABSTRACT FROM AUTHOR]

Abstract: The paper deals with numerical modeling and experimental testing of the clinched joint combined with an adhesive bonding. Two specimen manufacturing procedures were used to prepare overlap hybrid joint: adhesive curing before clinching, and clinching before adhesive curing. The strength of the joints was determined experimentally in the tensile test by pull and peel method. The experimental results were compared with numerical simulation results using ABAQUS code. The major conclusion of the paper is the following – clinching before adhesive curing is more effective technology for the joint strength. [Copyright &y& Elsevier]

Many additive manufacturing technologies involve the deposition of particles onto a surface followed by selective, targeted, laser heating. This paper develops a modular computational framework which combines the various steps within this overall process. Specifically, the framework synthesizes the following: Numerical examples are provided and extensions are also addressed for two advanced processing scenarios involving solid-liquid-gas phase transformations. [ABSTRACT FROM AUTHOR]

It is not uncommon to deal with very small experiments in practice. For example, if the experiment is conducted on the production process, it is likely that only a very few experimental runs will be allowed. If testing involves the destruction of expensive experimental units, we might only have very small fractions as experimental plans. In this paper, we will consider the analysis of very small factorial experiments with only four or eight experimental runs. In addition, the methods presented here could be easily applied to larger experiments. A Daniel plot of the effects to judge significance may be useless for this type of situation. Instead, we will use different tools based on the Bayesian approach to judge significance. The first tool consists of the computation of the posterior probability that each effect is significant. The second tool is referred to in Bayesian analysis as the posterior distribution for each effect. Combining these tools with the Daniel plot gives us more elements to judge the significance of an effect. Because, in practice, the response may not necessarily be normally distributed, we will extend our approach to the generalized linear model setup. By simulation, we will show that not only in the case of discrete responses and very small experiments, the usual large sample approach for modeling generalized linear models may produce a very biased and variable estimators, but also that the Bayesian approach provides a very sensible results. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper demonstrates a new methodology for designing a virtual factory model and model execution on the basis of a real schedule plan. The main characteristic of the developed method is that the inputs are regarded as one of the main parameters of the production process, and the main objective is to create a low-cost production process model. The methodology is adjusted for use in SMEs (Small and Medium-Sized Enterprises) with individual or unique type of production. For such companies, the method represents an ability to optimize existing production processes through detecting and eliminating possible errors and disturbances before the real production process is executed at an acceptable cost. The applicability and suitability of the developed method for virtual production performance has been proven with the verification process, where the input data for the simulation was obtained from a real company. The simulation results have shown that the presented methodology is a useful tool for the optimization of the production process. [ABSTRACT FROM AUTHOR]

Abstract: Sustainable manufacturing is a new paradigm in which manufacturing industries produce products in a sustainable manner while maintaining global competitiveness and coping with recent challenges and problems. Sustainable manufacturing research is very broad in scope and has not yet been firmly established at the academic or practical levels. This paper introduces MAS2, which is an integrated modeling and simulation-based life cycle evaluation approach for sustainable manufacturing. Four requirements that are essential for evaluating the sustainability performance of manufacturing industries are suggested. The proposed MAS2 approach consists of the following main components: 1) a theoretical foundation comprising 20 principles and definitions of sustainable manufacturing and manufacturing sustainability, 2) indicators, namely the MAS2 indicator and Manufacturing Sustainability Index (MSI), 3) e-MAS2 as an evaluation method, and 4) i-MAS2 as an information management method. The MAS2 system is developed based on the proposed approach, and consists of two main modules: MS-Modeler and MS-Simulator. The MAS2 approach and system are validated by application to the product life cycle of an automotive stamping shop. [Copyright &y& Elsevier]

Although high strengths up to 1,500 MPa can be obtained by means of hot stamping, the strength and uniformity of components cannot be guaranteed during mass production if the cooling channel is not properly designed. In this paper, we propose a method for designing the cooling channel by means of the energy balance principle and arrangement methods such as the triangular method, tool split, and the connection rule for 2D sections to improve the strength and uniformity of hot stamped components. Two separate approaches for designing the cooling channel are suggested. One is to reduce facility and maintenance costs, and the other is to reduce the cooling cycle time, which critically affects productivity. These approaches were applied to hot stamping tools for manufacturing a roof side that is used as part of the structure of an automobile. Cooling performance and cooling uniformity of the designed cooling channel were verified with finite element simulation. Finally, hot stamping tools for manufacturing a roof side were designed to reduce cooling cycle time and were then manufactured to verify the proposed design methods. A roof side was manufactured by means of the hot stamping tools with the designed cooling channel, and the strength and the uniformity of the component were evaluated by means of a tensile test, observation of the microstructure, and measurement of the micro-Vickers hardness. [ABSTRACT FROM AUTHOR]

This paper investigates how changes in chatter amplitude and frequency depend on process damping effect in dynamic turning process. For this purpose, the two degrees of freedom (TDOF) cutting system was modeled, and for an orthogonal turning system, the process damping model with a new simple approach was developed. To further explore the nature of the TDOF cutting model, a numerical simulation of the process was developed by this model. This simulation was able to overcome some of the weaknesses of the analytical model. The equations of motion for this cutting system were written as linear and nonlinear in the τ-decomposition form. The variation in the process damping ratios for different work materials was simply obtained by solving the nonlinear differential equations. A series of orthogonal chatter stability tests were performed for the identification of dynamic cutting force coefficients, using AISI-1040, Al-7075, and Al-6061 work materials, at a constant spindle speed. Finally, the experimental results were analyzed and compared with the simulation model, and it was observed that the results obtained through the experiments comply with the simulation model results. [ABSTRACT FROM AUTHOR]

Abstract: There is increasing evidence that more and more companies throughout the world are seeking measures to reduce their production carbon emissions and product carbon footprint. Simulation tools can be used to characterize the carbon emission dynamics of manufacturing system to help companies clearly developing the potential reduction strategies of production carbon emissions. On the basis of the carbon emissions dynamics described by general state equations of manufacturing system as a hybrid system, a simulation approach based on hybrid Petri-nets (HPN) is proposed to display the carbon emission dynamics. In order to estimate the total carbon emissions of the whole process chain, the carbon emissions of production system are represented as segments of specific carbon emissions for each operation state of the individual production equipments in the approach. Furthermore, two function indicators deriving from general state equations, carbon emission rate and carbon efficiency, are defined to describe the dynamic characteristics. Production disturbance as one of the critical factors influencing the carbon emission performance of production system is also considered in this paper for demonstrating their impacts on the carbon emission dynamic characteristics. Finally, an experimental study is presented to illustrate validation of the proposed approach and shows its positional significance for carbon emission reduction. [Copyright &y& Elsevier]

In experiments, it is usually difficult to accurately determine simulation input parameters such as heat source parameters, material properties at high temperature, etc. The uncertainty of such input parameters is responsible for the large error of thermal simulation for weld-based additive manufacturing. In this paper, a new approach is presented to calibrate uncertain input parameters. The approach is based on the solution of the inverse heat conduction problem of small-scale five-layer deposition and the application of the infrared (IR) imaging technique. The calibration of heat source parameters involves a multivariate optimization search using the pattern search method, whereas the calibration of the combined radiation and convection model includes a number of one-dimensional searches using the Fibonacci search method. Based on an in-depth analysis of IR images, thermal characteristics such as mean layer temperature and cooling rate are selected as the comparison results and included in cost functions. Lastly, the validity of the approach is demonstrated by a simulation case of 15-layer deposition with calibrated input parameters. The comparison between the simulated and experimental results verifies the improved prediction accuracy. [ABSTRACT FROM AUTHOR]

For a manufacturing equipment, any unplanned breakdown during the production period results into a high production loss. To keep the manufacturing facilities in good condition, preventive maintenance is planned. However, because of limited time and availability of resources, not all the system components can be or need to be repaired/replaced during a planned opportunity. Hence, the unplanned breakdowns can also be considered as an opportunity to do the maintenance activities for other components to take the advantage of economic dependency in multi-component system. However, when the system is under maintenance, it is very conservative to take the decision of maintenance actions on the components because of limited available time and resources. For such situation, this paper consider an opportunistic maintenance model for a multi-component system to take maintenance decision with a constraint on available time and the system availability requirements. The maintenance decisions for each component involves one of the three actions namely, repair, replace or do nothing to achieve the target availability with minimum maintenance cost. The model also considers the effect of component failures on the quality of product being manufactured as well as the production schedule on the machine. The cost of rejections is considered in the total failure cost along with the maintenance and downtime costs. The production schedule delay factor is considered as a constraint for the maintenance decision to account for the effect on production schedule delay. The optimal solution for the model is obtained using three solution methodologies namely simulated annealing, genetic algorithm and sequence heuristics. Using a real-life example of high pressure die casting machine, the opportunistic maintenance approach is demonstrated and results are discussed. [ABSTRACT FROM AUTHOR]

In this paper, we analyze a model of capacity sharing for a set of independent firms, geographically distributed, that often have to implement an opportune tool to integrate their resources and demand forecasts in order to gather a specific production objective. We formulate the problem as a cooperative game and identify a capacity sharing solution using the Gale-Shapley model. The allocation rule takes into account the utility functions of the involved firms, and we show how the capacity allocation rule can be designed to induce all firms to report truthfully their information. Moreover, we show that, under this allocation rule, truth telling is a dominant strategy, with each firm reporting truthfully its private information, regardless of the reporting decisions of other firms. Moreover, the proposed research develops a distributed approach able to facilitate the capacity sharing process by using a multi-agent architecture; then a discrete simulation environment has been developed to compare the proposed approach with a centralized one. Several simulation scenarios were conducted to analyze the performances' trends in various environment conditions. [ABSTRACT FROM AUTHOR]

Nowadays, high-speed machining is usually used for production of hardened material parts with complex shapes such as dies and molds. In such parts, tool paths generated for bottom machining feature with the conventional parallel plane strategy induced many feed rate reductions, especially when boundaries of the feature have a lot of curvatures and are not parallel. Several machining experiments on hardened material lead to the conclusion that a tool path implying stable cutting conditions might guarantee a better part surface integrity. To ensure this stability, the shape machined must be decomposed when conventional strategies are not suitable. In this paper, an experimental approach based on high-speed performance simulation is conducted on a master bottom machining feature in order to highlight the influence of the curvatures towards a suitable decomposition of machining area. The decomposition is achieved through the construction of intermediate curves between the closed boundaries of the feature. These intermediate curves are used as guidance curve for the tool paths generation with an alternative machining strategy called 'guidance curve strategy'. For the construction of intermediate curves, key parameters reflecting the influence of their proximity with each closed boundary and the influence of the curvatures of this latter are introduced. Based on the results, a method for defining guidance curves in four steps is proposed. [ABSTRACT FROM AUTHOR]

The impact of the disassembly process on the design of a product is a recognized fact, influencing recycling, maintenance, repair, and component/material re-using-essential aspects for a sustainable development. For simplifying and improving their work, as well as for designing proper and efficient disassembly plans, it is important for engineers to benefit from a disassembly method, for automatically generating dismounting sequences, incorporated in a software solution for providing rapid disassembly information that can be further used for real-time immersive simulations. The disassembly method proposed in this paper is based on two innovative elements: the connection interface concept and the mobility operator that integrates information on geometrical constraints, contact surface relative position and common area, neighboring components, and relative mobilities of the assembly components. All these data are corroborated with knowledge-based criteria and are used to generate a set of connection interfaces for a product to define mechanical joints, automating the identification of fasteners in the assembly and determining the components' mobility within assembly. As a consequence, it is possible to calculate and realistically simulate components' disassembly paths. In the proposed method, valid disassembly trajectories of a component relative to its surrounding ones are modeled based on the mobility operator, the swept volume approach is used to evaluate collisions between components, and finally, the disassembly sequences are determined through an improved layer peeling technique. [ABSTRACT FROM AUTHOR]

This paper describes the development of an affordable precision hybrid glass-polymer achromatic doublet fabricated by microinjection molding. This hybrid lens can be used to correct chromatic aberration by combining a flint and a crown glass. Specifically, polycarbonate was selected as the flint glass with higher dispersion and N-BK7 was selected for lower dispersion crown glass. Microinjection molding was utilized to apply the aspherical polycarbonate layer directly onto the N-BK7 glass lens' surface in this study for its capabilities of precision microfeature replication and mass production. In addition, finite element-based numerical simulation for molding process was employed to assist the design to improve the manufacturability. To ensure high precision in the fabricated hybrid lens, mechanical alignment features were created on the mold inserts to position the finished polymer lens along with the insert that housed the glass lens. The mold inserts' surfaces were diamond-turned to optically finished without polishing. It was demonstrated in this study that with properly designed manufacturing processes, an integrated hybrid glass-polymer lens could be fabricated without further mechanical alignment. Lastly, the optical performance of the hybrid lens was verified by focal shift evaluation. [ABSTRACT FROM AUTHOR]

In manufacturing systems, many maintenance tasks require equipment to be locked out for safety. However, such stoppage might directly cause short-term production losses although maintenance is performed to increase the long-term system reliability. In this paper, we investigate how long we can strategically stop equipment for maintenance during production operating without affecting system throughput. We extend the concept of maintenance opportunity windows (MOWs) to various system configurations and introduce a new concept of group maintenance opportunity windows (GMOWs). GMOW is the maximum time window that allows to perform a group maintenance without jeopardizing the flow of a production line. Moreover, we also provide how to calculate MOW and GMOW via simulations which can deal with uncertainties in production lines, such as random machine failures, starvations, blockages, etc. [ABSTRACT FROM AUTHOR]

In this paper, flexible manufacturing systems (FMS) are studied. Firstly, an FMS design approach is proposed using integrated definition for function methodology. A systematic layout design and performance evaluation scheme is presented and detailed using this modeling framework. Then, the proposed approach is carried out with a case study from an aircraft industry to convert an existing traditional production system to FMS. To improve the system performance, a simulation-based method with Taguchi approach consisting of multiproducts is utilized. The objective is to find the machine and the product mix that achieves the maximum utilization while minimizing the cycle time. FMS system performance has been greatly improved by determining the most advantageous level of system components. It has also shown that FMS is a practicable production system in aircraft industry. [ABSTRACT FROM AUTHOR]

This paper devotes both analytical and experimental efforts in developing a comprehensive dynamic model for an articulated steering wheel loader. The general motion of a wheel loader without suspension is described by seven degrees of freedom (DOF) (three for translation and four for rotation) in this model, which can be used to study the problem of wheel loader dynamics on slopes and over obstacles. A scale wheel loader was designed and manufactured to validate the dynamic model in three conditions (turning on level ground, turning on slopes, and passing over obstacles). The test results reasonably agree with the simulation results. The developed dynamic model was found to be useful and could serve as an important tool for analysing the stability of wheel loaders. [ABSTRACT FROM PUBLISHER]

Abstract: The aim of this paper is to develop and manufacture a thermoelectric structure operating in Peltier mode with non-standard materials, using a Finite Element Model. Thus, both the reliability of the Finite Element Model and the correct development and design of the new thermoelectric structure are ascertained, achieving a dual goal of our research group. This work provides a very good correlation between simulated and experimental results, and corroborates that the material's performance has a decisive influence on the thermoelectric properties of the structure in the temperature range of study considered. [Copyright &y& Elsevier]

Abstract: In the present paper a tri-dimensional non-linear dynamic thermohydraulic model of a parabolic trough collector was developed in the high-level acausal object-oriented language Modelica and coupled to a solar industrial process heat plant modeled in TRNSYS. The integration is performed in an innovative co-simulation environment based on the TLK interconnect software connector middleware. A discrete Monte Carlo ray-tracing model was developed in SolTrace to compute the solar radiation heterogeneous local concentration ratio in the parabolic trough collector absorber outer surface. The obtained results show that the efficiency predicted by the model agrees well with experimental data with a root mean square error of 1.2%. The dynamic performance was validated with experimental data from the Acurex solar field, located at the Plataforma Solar de Almeria, South-East Spain, and presents a good agreement. An optimization of the IST collector mass flow rate was performed based on the minimization of an energy loss cost function showing an optimal mass flow rate of 0.22kg/sm2. A parametric analysis showed the influence on collector efficiency of several design properties, such as the absorber emittance and absorptance. Different parabolic trough solar field model structures were compared showing that, from a thermal point of view, the one-dimensional model performs close to the bi-dimensional. Co-simulations conducted on a reference industrial process heat scenario on a South European climate show an annual solar fraction of 67% for a solar plant consisting on a solar field of 1000m2, with thermal energy storage, coupled to a continuous industrial thermal demand of 100kW. [Copyright &y& Elsevier]

Purpose: This paper describes a typical Value stream mapping (VSM) application enhanced by the discrete event simulation (DES) to a dedicated tubular manufacturing process. Design/Methodology/Approach: VSM is prescribed as part of lean production portfolio of tools, not only highlights process inefficiencies, transactional and communication mismatches, but also guides improvement areas. Meanwhile, DES is used to reduce uncertainty and create consensus by visualizing dynamic process views. It is served as a complementary tool for the traditional VSM to provide sufficient justification and quantifiable evidence needed to convince the lean approaches. A simulation model is developed to replicate the operation of an existing system, and that of a proposed system that modifies the existing design to incorporate lean manufacturing shop floor principles. Findings: A comprehensive model for the tubular manufacturing process is constructed, and distinctive scenarios are derived to uncover an optimal future state of the process. Various simulation scenarios are developed. The simulated results are acquired and investigated, and they are well matched with the real production data. Originality/Value: DES is demonstrated as a guided tool to assist organizations with the decision to implement lean approaches by quantifying benefits from applying the VSM. A roadmap is provided to illustrate how the VSM is used to design a desired future state. The developed simulation scenarios mimic the behavior of the actual manufacturing process in an intuitive manner. [ABSTRACT FROM AUTHOR]

Abstract: Ever increasing acceptance of electric vehicles relies on better operation and control of large battery packs. The individual modules in large battery packs cannot have identical characteristics and may degrade differently due to manufacturing variability and other factors. Degraded battery modules waste more power, affecting the performance and economy for the whole battery pack. Also, such impact varies with different trip patterns. It is beneficial if the performance gain can be evaluated online prior to replacing certain battery module regarding to actual driving. In this paper, the research objectives are two-fold. First, we propose an on-line battery module degradation diagnostic scheme using the intrinsic signals of battery module equalization. Without need for additional sensors or offline tests, this scheme is cost-effective for constructing and updating the battery pack “health map” in real time during the vehicle operation. Secondly, based on the derived battery health map, the Worthiness of Replacement (WOR) for certain modules/cells is proposed to evaluate the performance of the battery pack for customer specified trip. Such evaluation index provides a quantitative measure for module replacement and battery pack swapping Simulation study is performed to validate the proposed ideas using an actual driving cycle recorded for a commuting trip. [Copyright &y& Elsevier]

The paper presents a solution, which enables widening of more objective diagnostics and examination of operating conditions of production systems by AWJ technology following their economic effectiveness and competitiveness with the use of modelling and simulation. It contains the base of more complex diagnostics and factors, on which it is built. It presents a suggestion of experiment set for more complex diagnostics and the suggestion of sets for its evaluation. It also mentions expected benefits of the realisation of more complex diagnostics of operating conditions. [ABSTRACT FROM AUTHOR]

Due to the continuous growth in the application of networks in manufacturing, quality of service (QoS) has become an important issue. In this paper, the concept of QoS for manufacturing networks is discussed. To provide overall performance assurance for manufacturing networks, a service framework integrating the QoS mechanisms of the networked resource service management function and the communication networks is proposed. The novel framework maps an application to resource services and then to communication networks, adopts an intelligent optimisation algorithm for QoS management of resource services, and provides QoS schemes for data transfer across communication networks. A prototype implementation has been realised and a set of simulation experiments conducted to evaluate the validity of the framework. The results obtained demonstrate the ability of the framework to satisfy the various performance requirements posed by such applications and provide efficient overall performance assurance for manufacturing networks. [ABSTRACT FROM AUTHOR]