Showing papers on "Material flow published in 2015"
TL;DR: In this article, the authors present a project to map, in a high level of detail, the in-use construction material stocks of Japan and its 47 prefectures from the 1940s until the present era.
Abstract: In order to fully comprehend the socioeconomic metabolic (SEM) dynamics and material balance of nations, long-term accounting of economy-wide material stock is necessary in parallel to material flow accounts. Nevertheless, material stock accounts have been scarce, isolated, and mostly focused either on single materials, short time spans, or small regions. This study has two objectives: (1) review the state of the art of material stock research in the SEM discourse and (2) present a project to map, in a high level of detail, the in-use construction material stocks of Japan and its 47 prefectures from the 1940s until the present era. This project documents the two major depositories of material stock: buildings and infrastructure. We describe the challenges and benefits of utilizing a bottom-up approach, in order to promote its usage in material stock studies. The resulting database presents the accumulation of stock over time, as well as visually displaying the spatial distribution of the stock using geographical information systems (GIS), which, we argue, is an essential aspect of material stock analysis in the context of socioeconomic metabolism research
188 citations
TL;DR: In this article, a numerical method based on computational fluid dynamics is employed to quantitatively analyze the thermo-physical phenomena in friction stir welding with two tools of different pin shapes (axisymmetrical conical tool and asymmetrical triflat tool).
136 citations
TL;DR: In this article, material flow and plastic deformation in ultrasonic vibration enhanced friction stir welding are visualized by employing a special marker material and welding procedure, and three methods are developed to evaluate the volume of deformed material, the material flow velocity and the strain/strain rate.
129 citations
TL;DR: In this paper, the authors examined the global flows of materials and the amounts of materials directly and indirectly necessary to satisfy domestic final demand in different countries world-wide, by applying a global, multi-regional input-output (MRIO) model based on the GTAP database and extended by material extraction data.
Abstract: Material flow-based indicators play an important role in indicator sets related to green and resource-efficient growth. This paper examines the global flows of materials and the amounts of materials directly and indirectly necessary to satisfy domestic final demand in different countries world-wide. We calculate the indicator Raw Material Consumption (RMC), also referred to as Material Footprint (MF), by applying a global, multi-regional input-output (MRIO) model based on the GTAP database and extended by material extraction data. We examine world-wide patterns of material extraction and materials embodied in trade and consumption, investigating changes between 1997 and 2007. We find that flows of materials related to international trade have increased by almost 60% between 1997 and 2007. We show that the differences in Material Footprints per capita are huge, ranging from up to 100 tonnes in the rich, oil-exporting countries to values as low as 1.5 to 2 tonnes in some developing countries. We also quantify the differences between the indicators Domestic Material Consumption (DMC) and RMC, illustrating that net material exporters generally have a DMC larger than RMC, while the reverse is observed for net importers. Finally, we confirm the fact that most countries with stable or declining DMCs actually show increasing RMCs, indicating the occurrence of leakage effects, which are not fully captured by DMC. This challenges the world-wide use of DMC as a headline indicator for national material consumption and calls for the consideration of upstream material requirements of international trade flows.
125 citations
TL;DR: Co-location with suppliers appears to have beneficial effects to the reduction of disruption duration, and overall supply side factors have a higher impact when it comes to supply chain disruption risk than comparable customer side factors.
Abstract: In this article, we evaluate the relationship between supply chain design decisions and supply chain disruption risk. We explore two supply chain design strategies: (i) the dispersion of supply chain partners to reduce supply chain disruption risk versus (ii) the co-location of supply chain partners to reduce supply chain disruption risk. In addition, we assess supply chain disruption risk from three perspectives: the inbound material flow from the supplier (supply side), the internal production processes (internal), and the outbound material flow to the customer (customer side) as a disruption can occur at any of these locations. We measure disruption risk in terms of stoppages in flows, reductions in flow, close calls (disruptions that were prevented at the last minute), disruption duration (time until normal operation flow was restored), and the spread of disruptions all the way through the supply chain. We use seemingly unrelated regression (SUR) to analyze our data, finding that lead times, especially supply side lead times, are significantly associated with higher levels of supply chain disruption risk. We find co-location with suppliers appears to have beneficial effects to the reduction of disruption duration, and, overall supply side factors have a higher impact when it comes to supply chain disruption risk than comparable customer side factors.
92 citations
TL;DR: In this paper, the defect formation mechanism during friction stir welding (FSW) was investigated by the three-dimensional visualisation of material flow around a tool using two pairs of X-ray transmission real-time imaging systems.
Abstract: The defect formation mechanism during friction stir welding (FSW) was investigated by the three-dimensional visualisation of material flow around a tool. The three-dimensional flow patterns under various FSW conditions were obtained using two pairs of X-ray transmission real time imaging systems. The flow patterns revealed that the tilt of horizontal material flow around the tool and the stagnation of material flow on the advancing side (AS) of the tool were significantly correlated to the formation of defects. The material flow velocity during FSW was directly calculated based on the results of three-dimensional visualisation. The material flow velocity on the AS obviously decreased under the condition where defects were formed.
72 citations
TL;DR: In this article, a thin sheet made of heat-treatable aluminum alloy AA6082-T6 was joined by mechanical clinching using extensible dies and the influence of process conditions on material flow and mechanical behavior of clinched connections was investigated.
66 citations
TL;DR: In this article, an ultrasonic vibration enhanced friction stir welding (UVeFSW) system was developed, in which the ultrasonic energy was transmitted directly into the localized area of the workpiece near and ahead of the rotating tool by a specially-designed sonotrode.
62 citations
TL;DR: In this paper, the grain size of pure aluminum in the stir zone estimated by the Zener-Hollomon parameter using the obtained strain rate shows good agreement with that observed by Electron Back-Scatter Diffraction mapping.
55 citations
TL;DR: In this paper, a tracer material was embedded in the Ti-6Al-4V butt joint under a variety of process conditions, namely rotational speed and traversing speed, in an attempt to relate the welding process parameters to the material flow behavior via post weld radiographic and metallographic evaluations.
45 citations
TL;DR: A calibrated and validated dynamic material flow model of Austrian aluminum (Al) stocks and flows between 1964 and 2012 was developed and constituted a reliable basis for evaluating future recycling potentials, in particular with respect to application-specific qualities of current and future national Al scrap generation and utilization.
Abstract: A calibrated and validated dynamic material flow model of Austrian aluminum (Al) stocks and flows between 1964 and 2012 was developed. Calibration and extensive plausibility testing was performed to illustrate how the quality of dynamic material flow analysis can be improved on the basis of the consideration of independent bottom-up estimates. According to the model, total Austrian in-use Al stocks reached a level of 360 kg/capita in 2012, with buildings (45%) and transport applications (32%) being the major in-use stocks. Old scrap generation (including export of end-of-life vehicles) amounted to 12.5 kg/capita in 2012, still being on the increase, while Al final demand has remained rather constant at around 25 kg/capita in the past few years. The application of global sensitivity analysis showed that only small parts of the total variance of old scrap generation could be explained by the variation of single parameters, emphasizing the need for comprehensive sensitivity analysis tools accounting for inte...
TL;DR: In this paper, the material flow in friction stir spot welding of aluminium to both aluminium and steel has been investigated, using pinless tools in a lap joint geometry, and the flow behaviour was revealed experimentally using dissimilar Al alloys of similar strength.
TL;DR: In this paper, the authors deal with the modeling of the material flow in Friction Stir Welding (FSW) processes using particle tracing method, and three accurate and computationally efficient integration methods are implemented within a FE model: the Backward Euler with Sub-stepping (BES), the 4th order Runge-Kutta (RK4) and the Back and Forth Error Compensation and Correction (BFECC) methods.
Abstract: This work deals with the modeling of the material flow in Friction Stir Welding (FSW) processes using particle tracing method. For the computation of particle trajectories, three accurate and computationally efficient integration methods are implemented within a FE model for FSW process: the Backward Euler with Sub-stepping (BES), the 4-th order Runge–Kutta (RK4) and the Back and Forth Error Compensation and Correction (BFECC) methods. Firstly, their performance is compared by solving the Zalesak’s disk benchmark. Later, the developed methodology is applied to some FSW problems providing a quantitative 2D and 3D view of the material transport in the process area. The material flow pattern is compared to the experimental evidence.
TL;DR: This paper demonstrates a novel interoperable approach to physical analysis on as-manufactured part geometry represented as a collection of machine-specific cross sections augmented with boundary conditions defined on the nominal geometry that only relies on fundamental queries of point membership classification and distance to boundary and therefore does not involve the overhead of model preparation required in approaches such as finite element analysis.
Abstract: Representations of solid models were initially formulated partially in response to the need to support automation for numerically controlled machining processes. The assumed equivalence between shape, topology, and material properties of manufactured components and their computer representations led to the practice of modeling and simulating the behavior of physical parts before manufacture. In particular, representations of shape and material properties are treated in distinct nominal models for most unit manufacturing processes. Additively manufactured parts usually exhibit deviations from their nominal geometry in the form of stair-stepping artifacts and topological irregularities in the vicinity of small features. Furthermore, structural properties of additively manufactured parts have experimentally been shown to be dependent on the build orientation defining the cross sections where material is accumulated. Therefore geometric models of additively manufactured parts cannot be decoupled from the manufacturing process plan.In this paper we show that as-manufactured shapes may be represented in terms of the convolution operation to capture the additive deposition of material, measure the conformance to nominal geometry in terms of overlap volume, and model uncertainties involved in material flow and process control. We then demonstrate a novel interoperable approach to physical analysis on as-manufactured part geometry represented as a collection of machine-specific cross sections augmented with boundary conditions defined on the nominal geometry. The analysis only relies on fundamental queries of point membership classification and distance to boundary and therefore does not involve the overhead of model preparation required in approaches such as finite element analysis. Results are shown for non-trivial geometries to validate the proposed approach. Representation of as-manufactured models using convolution.Incorporating manufacturing uncertainty into representation.Computing as-manufactured models using planar morphological operations.Interoperable analysis using query based simulation on sliced as-manufacturable models.
TL;DR: In this article, the impact of sector aggregation bias in Environmentally Extended Input Output (EEIO) models, focusing on raw material flows, was investigated and the results showed that industries with high raw material use deserve special attention in EEIO models.
TL;DR: In this article, the authors developed a conceptual sustainable packaging model that integrates the variables of technical design, supply chain systems and environmental factors and then used the model to identify to improve upon corrugated container design.
Abstract: Corrugated package designers are focused on balancing the need for product protection, material use efficiency and the packaging material's impact on the environment in the supply chain. The purpose of this paper is to develop a conceptual sustainable packaging model that integrates the variables of technical design, supply chain systems and environmental factors and then use the model to identify to improve upon corrugated container design.
A model was developed, from the extant literature, and a case study was performed on a corrugated container. This is believed to be a unique integrated model of most relevant agents related to the design and implementation of a corrugated box through a supply chain from design to potential post-consumer reuse.
From this study, we found opportunities to improve the environmental design of the corrugated container through four ex ante design stages, and two ex post facto supply chain stages. Further, research can evaluate and refine this model via a ‘live supply chain’ for use in guiding corrugated box material selection design and reuse/recycling. Integration of the design criterion for a unit load in the supply chain creates opportunity to observe the packaging system holistically. Waste in the manufacturing process and CO2 emissions are traced along the material flow until the end of its useful life to provide an overall picture of the packaging system. Copyright © 2014 John Wiley & Sons, Ltd.
TL;DR: In this article, a three-dimensional computational fluid dynamics code, FLUENT, was used to model the heat and material flow during FSW of SS304 using the polycrystalline cubic boron nitride pin.
Patent•
14 Sep 2015
TL;DR: In this paper, a harvesting machine capable of automatic adjustment, comprising a plurality of acoustic material flow sensors, a control system, a processor, and application software, is presented, where the software uses information sensed by the acoustic flow sensors to determine if the internal elements of the harvesting machine are set for optimal machine performance.
Abstract: A harvesting machine capable of automatic adjustment, comprising a plurality of acoustic material flow sensors, a control system, a processor, and application software, wherein the plurality of acoustic material flow sensors are mounted internal to the harvesting machine at points of crop material flow and are capable of sensing an amount of crop material passing by them, wherein the control system is capable of adjusting a plurality of internal elements of the harvesting machine, wherein the software is hosted on the processor, and the processor is operatively coupled to the control system and the acoustic material flow sensors, wherein the software uses information sensed by the acoustic material flow sensors to determine if the internal elements of the harvesting machine are set for optimal machine performance, and the software sends commands to the internal elements of the harvesting machine in order to improve the machine performance.
TL;DR: In this paper, a contour extraction solution is proposed in accordance with the space's morphological characteristics and the material flow outline in one frame, and a mathematical model to calculate the flow rate of bulk materials on moving belt is established.
TL;DR: Friction taper plug welding experiment was conducted on X65 pipeline steel in underwater wet condition as discussed by the authors, which showed that the weld defects, microstructural evolution and mechanical properties are closely related to the material flow behavior during welding.
TL;DR: This paper proposes a framework for “material flow assessment in manufacturing” that promotes greater understanding of material flow and flexibility to explore innovative options for improvement, and highlights the benefits ofmaterial flow modeling within manufacturing systems to support advances in increased material efficiency.
Abstract: Improving material efficiency is widely accepted as one of the key challenges facing manufacturers in the future. Increasing material consumption is having detrimental impacts on the environment as a result of their extraction, processing, and disposal. It is clear that radical improvements in material efficiency are required to avoid further environmental damage and sustain the manufacturing sector. Current resource management approaches are predominantly used to improve material consumption solely in economic terms. Meanwhile, environmental assessment methodologies can determine sources of significant environmental impact related to a product; however, a methodology to effectively assess material efficiency in production systems is currently not available. This paper highlights the benefits of material flow modeling within manufacturing systems to support advances in increased material efficiency, proposing a framework for “material flow assessment in manufacturing” that promotes greater understanding o...
TL;DR: In this paper, two panoramic MFA analyses of the Hebei iron and steel industry in 2005 and 2010 were conducted respectively, which form a continuous analysis of scale, structure, and efficiency in material metabolism for HISI.
Abstract: The application of material flow analysis (MFA) as a tool produces an objective assessment on scale, structure, operation efficiency and other aspects of the development of iron and steel industry in Hebei Province. This study is based on the framework of “Economy-wide material flow accounts and derived indicators: A methodological guide;” however, some necessary corrections have been made for the analysis of material metabolism according to the characteristics of industrial MFA and the reality in the Hebei iron and steel industry (HISI). Two panoramic MFA analyses of HISI in 2005 and 2010 were conducted respectively, which form a continuous analysis of scale, structure, and efficiency in material metabolism for HISI. The results show that between 2005 and 2010, there was a rapid development of HISI as a result of huge consumption of resource and energy. Between these years, the material inputs and material consumption increased by 3.30 times and 4.98 times, respectively, leading to serious environmental degradation and significant waste of resource and energy. Although the scale of material metabolism kept increasing, the rate of increase slowed. Hence, the total amount of waste emission increased year after year; specifically, gas waste witnessed an increase of 9.7% each year. Clearly, there is an excessive and growing dependence on primary energy resources. The amount of iron ore imports increased 2.61 times in 2010 compared to 2005. In order to achieve sustainable development in HISI, we recommend the following: improving technologies, strengthening material recycling, and promoting circular economy.
TL;DR: It is shown that the mathematical programming representation used for discrete-event systems with a continuous time and mixed continuous-discrete state space is also a viable method for performance evaluation and optimization of continuous material flow systems.
Abstract: This study presents a mathematical programming representation of discrete-event systems with a continuous time and mixed continuous-discrete state space. In particular, continuous material flow production systems are considered. A mathematical programming representation is used to generate simulated sample realizations of the system and also to optimize control parameters. The mathematical programming approach has been used in the literature for performance evaluation and optimization of discrete material flow production systems. In order to show the applicability of the same approach to continuous material flow systems, this article focuses on optimal production flow rate control problems for a continuous material flow system with an unreliable station and deterministic demand. These problems exhibit most of the dynamics observed in various continuous flow productions systems: flow dynamics, machine failures and repairs, changing flow rates due to system status, and control. Moreover, these problems incl...
TL;DR: In this article, a local eigen model of transitional region in the local loading forming of large-scale rib-web component is extracted so as to catch the detail-forming characteristics of transitional regions with low computation time in simulation and experiment cost.
Abstract: The forming quality of transitional region plays a key role in the performance of titanium alloy large-scale rib-web component under isothermal local loading forming. In this work, a local eigen model of transitional region in the local loading forming of large-scale rib-web component is extracted so as to catch the detail-forming characteristics of transitional region with low computation time in simulation and experiment cost. Then, based on the local eigen model, the mechanism of forming defects in transitional region and their dependence on processing parameters are studied by the combination of physical experiment and verified finite element (FE) simulation. It is found that the second loading step can be divided into two forming stages according to the material flow pattern: (1) the transverse flow stage and (2) the stable forming stage. In the transverse flow stage, there exists long-range transverse flow of web material and excessive transverse flow would lead to the formation of folding and cavum defects. Moreover, the severities of defects are well correlated with the quantity of material transferred into the first-loading region in this stage. For a certain reduction amount, decreasing spacer block thickness and increasing friction both can decrease the quantity of transferred material and then suppress the development of folding and cavum defects, while the deformation temperature and loading speed have little effect on the quantity of transferred material and defects. In the end, an effective way is put forward to suppress and prevent the defects in transitional region during the local loading forming of titanium alloy large-scale rib-web component.
01 Jan 2015
TL;DR: A model which integrates mentioned criteria in supply chain management (SCM) and a new method for calculation of fitness function in genetic algorithm (GA) process is proposed and the result obtained from the model shows that it is robust.
Abstract: This research proposes a mathematical model for supply, production and distribution.For solving the model, it proposed e new methodology based on GA, FAHP and TOPSIS.The result of model shows that it is robust.It can also be applied to other industrial environments with slight modifications. In designing a supply chain (SC) system, the problem arises when a company has unsatisfactory inventory control policy and material routing between supplier-producer and distributor in SC considering specified cost and demand. The integration of decisions of different functions into a single optimization model is the base of this research. The aim of this paper is to study and compare the existing models of supply, production and distribution in SC and propose a model which integrates mentioned criteria in supply chain management (SCM). Furthermore, it proposes a new method for calculation of fitness function in genetic algorithm (GA) process. The successful designing of this model has led us to explore the use of heuristic methods such as GA to quantify the flow of SC, information and material flow. At first, fuzzy analytic hierarchy process (FAHP) is adapted to evaluate objective function weights in SC. Then final weights of objective function are determined by the technique for order of preference by similarity to ideal solution (TOPSIS). This research also simulated the real company SC operations, and determines the most effective strategic and operational policies for an effective SC system. The result obtained from the model shows that it is robust. This model can also be applied to other industrial environments with slight modifications.
TL;DR: In this article, the flow behavior of AA6061 under a threaded tool has been studied, and the convective heat loss has been considered from all the surfaces, and a comparative study has been made with and without the use of temperature-dependent properties and their significance in the finite volume method model.
Abstract: Friction stir welding has been quite successful in joining aluminum alloy which has gained importance in almost all industrial sectors over the past two decades. It is a newer technique and therefore needs more attention in many sectors, flow of material being one among them. The material flow pattern actually helps in deciding the parameters required for particular tool geometry. The knowledge of material flow is very significant in removing defects from the weldment. In the work presented in this paper, the flow behavior of AA6061 under a threaded tool has been studied. The convective heat loss has been considered from all the surfaces, and a comparative study has been made with and without the use of temperature-dependent properties and their significance in the finite volume method model. The two types of models that have been implemented are turbulent and laminar models. Their thermal histories have been studied for all the cases. The material flow velocity has been analyzed to predict the flow of material. A swirl inside the weld material has been observed in all the simulations.
TL;DR: A dynamic material flow control in mixed model assembly lines is proposed based on in-plant milk run principle and outperforms the traditional methods of material flow planning.
TL;DR: Wang et al. as discussed by the authors employed the dynamic material flow model to estimate the material flows and stocks of WWTIs and the associated carbon dioxide (CO2) emissions through 2050, considering effects of a rise in water consumption, a longer lifetime, and an increased material recycling rate.
Abstract: Wastewater treatment infrastructure (WWTI) construction in China has entered an accelerated stage of development in recent years as a result of rapid economic growth, urbanization, and the demand for improving water quality. As a result, a large amount of resources and materials will be allocated for the WWTI, and it is particularly important to find ways to reduce resource consumption effectively so that social dematerialization and sustainable development can be achieved. In this study, we employed the dynamic material flow model to estimate the material flows and stocks of WWTIs and the associated carbon dioxide (CO2) emissions through 2050, considering effects of a rise in water consumption, a longer lifetime, and an increased material recycling rate. Our results indicate that material consumption in WWTIs will increase rapidly through 2025 to meet the needs of the increased volume of discharged wastewater as well as to overcome the shortage of existing wastewater treatment plants. In contrast with the moderate effects of rise in water consumption, prolonging the lifetime will greatly reduce material consumption in WWTI construction during the period 2030–2050, and approximately 60% of the total material input will be saved in the medium-lifetime scenario, compared with the short-lifetime scenario. Material output and CO2 emissions associated with WWTIs will be reduced by 87% and 37%, respectively, in the medium-lifetime scenario, compared with the short-lifetime scenario, under high-water-consumption growth. Our results highlight the great importance of pipeline construction and cement consumption in resource consumption associated with WWTI construction in China. Moreover, this study also examined the potential ways to reduce material consumption in WWTI construction in the context of the demand chain, the design, construction, operation and management, and demolition.
11 Apr 2015-Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science
TL;DR: In this paper, a coupled numerical model of a special friction-stir process was developed to visualize the material flow patterns and temperature distribution on the surface of a cast AlSi9Mg aluminum alloy.
Abstract: Utilizing a tool without a pin, cast AlSi9Mg aluminum alloy was modified by friction-stir processing. Since the tool design specifically targets the microstructure within the surface layers, the process is more appropriately termed friction-stir surfacing. A coupled numerical model of this special friction-stir process was developed to visualize the material flow patterns and temperature distribution. As the tool transports surface material from the leading edge toward the retreating side of the tool, the material follows the scroll of the tool shoulder toward the tool center with each tool rotation. At or near the tool center, the material flows into the workpiece thickness, forming the vortex of a process zone. Depending on the processing conditions, i.e., tool velocity and rotation speed, an upward material flow also develops within the process zone. Due to the flow of cooler, unprocessed material into the process zone, the temperature profile on the tool/workpiece interface is skewed toward the advancing side and leading edge with higher processing temperatures occurring in these locations. However, the process parameters influence the shape and magnitude of the temperature distribution on this surface.
TL;DR: In this paper, a hierarchy of models for material flow problems ranging from detailed microscopic, discrete element method type, models to macroscopic models using scalar conservation laws with non-local interaction terms is presented at all levels of the hierarchy.
Abstract: Material flow simulation is in increasing need of multi-scale models On the one hand, macroscopic flow models are used for large-scale simulations with a large number of parts On the other hand, microscopic models are needed to describe the details of the production process In this paper, we present a hierarchy of models for material flow problems ranging from detailed microscopic, discrete element method type, models to macroscopic models using scalar conservation laws with non-local interaction terms Numerical simulations are presented at all levels of the hierarchy, and the results are compared to each other for several test cases