Showing papers on "Material flow published in 2002"
TL;DR: This paper presents an approach to manage inventory decisions at all stages of the supply chain in an integrated manner that allows an inventory order policy to be determined, aimed at optimizing the performance of the whole supply chain.
181 citations
28 May 2002
TL;DR: Material flow analysis (MFA) refers to the analysis of the throughput of process chains comprising extraction or harvest, chemical transformation, manufacturing, consumption, recycling and disposal of materials as discussed by the authors.
Abstract: Material flow analysis (MFA) refers to the analysis of the throughput of process chains comprising extraction or harvest, chemical transformation, manufacturing, consumption, recycling and disposal of materials. It is based on accounts in physical units quantifying the inputs and outputs of those processes. In general MFA provides a system-analytical view of various interlinked processes and flows to support the strategic and priority-oriented design of management measures. There is no general consensus on a methodological framework for materials accounting and flow analysis, the procedure and some elements of the studies have essential features in common. MFA-based indicators have been introduced in official reports to provide an overview on the headline issues of resource use, waste disposal and emissions to air and water as well as eco-efficiency. Economy-wide material flow accounts provide a more comprehensive picture of the industrial metabolism than single indicators.
120 citations
TL;DR: In this article, the repeated adiabatic shear band formation that takes place at sufficiently large cutting speeds in a number of materials during high-speed machining operations with the more well-known formation of a single shear bands that often takes place in dynamic torsion tests on these materials.
110 citations
TL;DR: In this article, the authors applied the finite element method to obtain a better understanding of the plastic deformation behavior of the workpiece during ECAP in terms of material flow properties and die geometries.
73 citations
TL;DR: In this article, an evolutionary algorithm (EA) is proposed for optimal synchronization of supply chains, which is shown to be much faster at solving large problems than an enumeration procedure and exhibits robust behavior when tested on a variety of different problem parameters.
70 citations
TL;DR: A multi-agent system (MAS) that can be used to simulate the dynamic behaviour and support the management of chemical supply chains over the Internet and an optimum scheduling system for batch plants is integrated into the MAS.
Abstract: Modern chemical production is customer-driven and the desired delivery time for the products is often shorter than their campaign length. In addition, the raw materials supplying time is often long. These features make it desirable to provide tools to support collaborative supply chain decision making, preferably over the Internet, and where there are conflicts, compromise decisions can be quickly reached and the effects of the decisions can be quantitatively simulated. This paper des cribes such a multi-agent system (MAS) that can be used to simulate the dynamic behaviour and support the management of chemical supply chains over the Internet. Geographically distributed retailers, logistics, warehouses, plants and raw material suppliers are modelled as an open and re-configurable network of co-operative agents, each performing one or more supply chain functions. Communication between agents is made through the common agent communication language KQML (knowledge query message language). A t the simulation layer, the MAS allows distributed simulation of the chain behaviour dynamically, so that compromise decisions can be rapidly and quantitatively evaluated. Because in a chemical supply chain the scheduling of the plant often dominates the chain performance, an optimum scheduling system for batch plants is integrated into the MAS. The functions of the system are illustrated by reference to a case study for the supply and manufacture using a multi-purpose batch plant of paints and coatings.
67 citations
01 Jan 2002
46 citations
TL;DR: In this article, a coupled thermo-mechanical model for the analysis of plastic deformation and heat transfer is adapted in the finite element formulation to consider the strain-rate effects on material properties and the flow stress dependence on temperatures.
44 citations
Journal Article•
TL;DR: In this paper, a survey presents crisp and fuzzy models developed for the supply chain (SC) developed for manufacturing and service industries, with reference to different aspects of an SC system, with respect to different fuzzy models for different SC systems and compare them with related crisp models.
Abstract: This survey presents crisp and fuzzy models developed for the Supply Chain (SC). To this end, fuzzy concepts are first
briefly reviewed. Then the structure of a supply chain system is explained. Recent challenges and ideas on these systems
are also surveyed. Then, with reference to different aspects of an SC system, we classify the recent fuzzy models developed
for different SC systems and compare them with related crisp models. Applications of the SC in manufacturing and service
industries are investigated in each case.
43 citations
TL;DR: A novel method for simulation of flows with dynamic interfaces based on a Lagrangian flow formulation and dynamic finite element meshes that easily handles interface-dominated flows and promises highly successful applications to complex flows including the target problem of microstructural blood flow simulation.
33 citations
TL;DR: In this paper, a new optical sensor for contactless on-line material flow measurement and its application for closed-loop process control in sheet metal forming is presented, which can be utilized as the controlled variable for closed loop control, as this value originates directly from the process and can be used to characterize the process course.
TL;DR: In this article, a non-steady thermo-rigid-viscoplastic finite element program was developed for numerical simulations of the extrusion process and an automatic remeshing module based on a simple section-sweeping scheme and new contact algorithm were incorporated to allow continuous simulation without manual intervention with less volume loss and computation time.
01 Dec 2002
TL;DR: In this paper, the authors presented preliminary results of a material flow analysis (MFA) of the Hungarian economy for to years 1993-1997, showing that only a relative decoupling of material flows and economic activity has taken place during the last years.
Abstract: This report presents preliminary results of a material flow analysis (MFA) of the Hungarian Economy for to years 1993-1997. Material flow based indicators like Direct Material Input (DMI) and Total Material Requirement (TMR) are used as environmental sustainability indicators. The analysis of the structure of the material flows shows the share of domestic and foreign components and the shares of several material categories. The time series demonstrates that only a relative decoupling of material flows and economic activity has taken place during the last years. Although a decrease of the indicators per GDP during the last years of the analyzed period could be observed both material flows in absolute numbers and material flows per capita have increased. Material intensity of the Hungarian economy in terms of material requirement per economic output is higher -- and vice versa material efficiency is lower -- compared to Western Industrialized Countries. In contrast material inputs per capita are lower than in most Western Countries. The paper closes with a methodological discussion of the applied indicators and policy and research implications.
TL;DR: In this paper, a new method combining compression tests with FEM simulation (C-FEM) is described, where the flow stress is applied in the analysis of compression tests, and a target function for evaluating flow-stress precision is set up.
TL;DR: In this paper, the authors examined which material planning methods companies are using, to what extent these methods are perceived as efficiently supporting the operation, how the various methods are applied, and how the satisfied users apply the methods.
Abstract: Methods for planning and control of the flow of material in the manufacturing enterprise are more or less appropriate to use in a specific situation, mainly depending on the existing planning environment. How well they contribute to an effective material flow is also depending on how they are applied. This paper examines which material planning methods companies are using, to what extent these methods are perceived as efficiently supporting the operation, how the various methods are applied, and how the satisfied users apply the methods. The findings are based on a survey study carried out in 84 manufacturing companies in Sweden in 2000. From the results some conclusions concerning state-of-the-art application of material planning methods in the manufacturing industry are presented. A comparison with a similar study on the same population from 1993 is also conducted. The findings show that material requirements planning is generally the most used method. The most common ways to determine planning paramete...
TL;DR: An optical sensor to measure granular fertilizer flow in an airstream was designed, built, and laboratory tested in this article, where the sensor components included a laser line generator that transmitted light across a trapezoidal chamber to a 32-element photodiode array.
Abstract: An optical sensor to measure granular fertilizer flow in an airstream was designed, built, and laboratory tested. The sensor components included a laser line generator that transmitted light across a trapezoidal chamber to a 32-element photodiode array. The air-suspended granules would break the light, causing a count to be recorded. The counts were translated into a mass flow rate. Static tests of five materials and six mass flow rates were performed in a replicated block design. Dynamic tests of one material with six step changes in mass flow rate were performed. Results of the static tests showed a strong linear, repeatable relationship between sensor output and mass flow rate. For maximum accuracy, individual calibrations were required for different fertilizer products. Dynamic test results showed that the sensor followed step changes in mass flow rate well, but indicated some limitations in the data analysis algorithm. The optical sensor system showed potential as a first step to a real-time granular fertilizer flow rate sensor.
07 Aug 2002
TL;DR: By incorporating stochastic Petri nets with the batch features, inhibitor arcs, and marking-dependent weights, operational policies of a supply chain can be easily described in the model.
Abstract: Batch deterministic and stochastic Petri nets are developed as a new tool for modeling and performance evaluation of supply chain. It is derived by enhancing deterministic and stochastic Petri nets. with batch places and batch tokens. Batch tokens, which have sizes and reside in batch places, are used to describe the information flow of a supply chain, while discrete tokens residing in discrete places are used to describe the material flow and the financial flow. By incorporating stochastic Petri nets with the batch features, inhibitor arcs, and marking-dependent weights, operational policies of a supply chain can be easily described in the model. A real-life supply chain is modeled by applying this tool and its performance is evaluated and optimized by simulation.
01 Jan 2002
TL;DR: An optical sensor to measure granular fertilizer flow in an airstream was designed, built, and laboratory tested in this article, where the sensor components included a laser line generator that transmitted light across a trapezoidal chamber to a 32-element photodiode array.
Abstract: An optical sensor to measure granular fertilizer flow in an airstream was designed, built, and laboratory tested. The sensor components included a laser line generator that transmitted light across a trapezoidal chamber to a 32-element photodiode array. The air-suspended granules would break the light, causing a count to be recorded. The counts were translated into a mass flow rate. Static tests of five materials and six mass flow rates were performed in a replicated block design. Dynamic tests of one material with six step changes in mass flow rate were performed. Results of the static tests showed a strong linear, repeatable relationship between sensor output and mass flow rate. For maximum accuracy, individual calibrations were required for different fertilizer products. Dynamic test results showed that the sensor followed step changes in mass flow rate well, but indicated some limitations in the data analysis algorithm. The optical sensor system showed potential as a first step to a real-time granular fertilizer flow rate sensor.
07 Jan 2002
TL;DR: This paper presents a method for modeling the dynamic behavior of harbor supply chains and evaluating strategic and operational policies of the proposed harbor supply chain by applying multiagent systems and simulation.
Abstract: This paper presents a method for modeling the dynamic behavior of harbor supply chains and evaluating strategic and operational policies of the proposed harbor supply chain by applying multiagent systems and simulation. The multiagent systems modeling represent business entities as agents and the involved information and material flows with proposed coordination method for collaborating among agents. The simulation model is applied to quantifying the flow of supply chain, information and material flow, and conducted to simulate the global harbor supply chain operations, and determined which strategic and operational policies are the most effective in smoothing the variations in the supply chain.
Posted Content•
TL;DR: In this paper, the Umberto software is used for modeling and analysis of operational material flow systems in practical applications, and the authors describe the performance and monetary evaluations and analysis possibilities using material flow networks.
Abstract: The modelling and analysis of operational material flow systems in practical applications has become increasingly important. The method of the material flow networks has been demonstrated to be a powerful instrument for the execution of widely diverse analyses. By the clean methodical separation of quantity and value levels the user is able to tap into an unusually large scope of applications. This contribution explains the methodical background of material flow networks and describes how it is rendered using the software Umberto®. Important points are the performance and monetary evaluations and analysis possibilities using material flow networks.
TL;DR: In this paper, the changing rule of the flow stress of AISI 1006 in the temperature range of warm forging has been analyzed systematically through thermo-mechanical experiments.
Patent•
24 Sep 2002TL;DR: In this paper, a microwave-heating chamber, for heating a ceramic, having an entrance and an exit end and a material flow axis along which the ceramic articles are conveyed, is designed for continuous drying of ceramic articles which produces little or no microwave radiation emission.
Abstract: The invention is directed at an apparatus capable of the continuous drying of ceramic articles which produces little or no microwave radiation emission. The drying apparatus comprises comprise a microwave-heating chamber, for heating a ceramic, having an entrance and an exit end and a material flow axis along which the ceramic articles are conveyed. Positioned adjacent the entrance and exit ends of the microwave-heating chamber, respectively, are a first and second attenuation chamber each having an entrance and an exit end. An inlet chamber, having a material flow path, is connected to the entrance end of the first attenuation chamber with a portion of the material flow path disposed at an angle to the flow axis. Connected to the exit end of the second attenuation chamber is an outlet chamber having a second material flow path; again at least a portion of the material flow path is at an angle to the material flow axis.
TL;DR: In this unique cell formation process, a divide and conquer algorithm is proposed to quickly estimate the intercell material movement cost that includes both forward flow and backward flow, instead of the typical measure that minimizes the number of intercell movements.
TL;DR: In this article, the simulation of different cold and warm forging processes, based on the application of the finite element software MSC, is presented with special emphasis on the occurrence of fracture in the ductile material failure of the ferrous materials used.
Patent•
15 Mar 2002TL;DR: In this article, a computer-aided determination process comprises feeding input variables (theta, s) to a material flow model (18) which describes a metal strip before and after the passing through a roll stand.
Abstract: Computer-aided determination process comprises feeding input variables (theta, s) to a material flow model (18) which describes a metal strip before and after the passing through a roll stand. The material flow model determines a rolling force progression (fR(z)) in the strip width direction (z) and feeds the progression to a roller deformation model (7). The roller deformation model determines roller deformations from the progression and feeds then to a desired calculator (11). The calculator calculates the desired values for the controlling elements of profile and surface evenness using the calculated roller deformations and a contour progression on the runout side. An Independent claim is also included for a computer program product for carrying out the above process. Preferred Features: The material flow model determines a two-dimensional distribution of the rolling force, in which direction extends in the rolling direction and one direction extends in the strip width direction.
TL;DR: In this paper, the effect of energy losses due to impact into the study of dynamic flow stress of a material is examined, assuming loss of kinetic energy varying from 1 to 20% of the initial energy.
01 Jan 2002
TL;DR: In this paper, a 3D finite element model of the Conform process was used to investigate the internal shearing in the extrusion chamber and to optimize the flow of the material within the chamber and reduce the possible defects in the final product.
Abstract: Summary In this work, FEM modeling of Conform extrusion was studied. The material model was viscoplastic and thermally coupled. The Abaqus/Explicit and Deform-3D codes were used for the simulation. Our results show that there is considerable internal shearing within the extrusion chamber. This is consistent with our earlier findings based on 2D simulation of the Conform process. The results also show that it may be possible to optimize the flow of the material within the chamber and thus reduce the possible defects in the final product. In addition, contact pressure on the tools may be reduced by proper design, which is expected to increase the tool life. Keywords: CONFORM process, finite element analysis 1 Introduction Continuous extrusion (Conform) of aluminum rod has been a commercial process since the late 70s[1-3]. Over the past decade, the Conform process has become established as a viable extrusion method for copper products. This versatile method enables the extrusion of long products such as shapes and profiles in virtually limitless lengths, when using continuously cast feed-rod. Continuous extrusion is particularly beneficial for processing non-ferrous metals such as aluminum and copper, which require breakdown processing of the cast grain structure. A cast or coarse grain structure can be transformed into uniform fine-grained metal (10-20 µm) in a single pass. Copper, in contrast to aluminum, will lead to significantly higher tool contact pressures and process temperatures. Consequently, the tool material requirements for copper are more demanding, which increases the tool costs. It is believed that a better understanding of the processing conditions in Conform extrusion will help in improving the overall cost-efficiency of the process. The Conform process was analyzed theoretically by Green [1] and Etherington [3]. Peng [4] made an investigation into material flow on the process using lead as model material. A 2D finite element model for Conform extrusion of copper was published in 1993 by Reinikainen et al. [5]. The material flow in Conform, however, is not two-dimensional. Recently, Velay [6] and Cho [7] have used full 3D finite element models to investigate Conform extrusion of aluminum.
Patent•
15 May 2002
TL;DR: In this paper, the authors proposed an improved vertical shaft impact crusher which consists of a cylinder body, a vibrosieve diffluent system and a power rotator throwing plate.
Abstract: The utility model provides an improved vertical shaft impact crusher which consists of a cylinder body, a vibrosieve diffluent system and a power rotator throwing plate, wherein, the proportion of the rotator material flow and the peripheral material flow can be adjusted via the vibrosieve diffluent system, the best condition can be ensured by changing the size of the sieve pore of the vibrosieve, and the material of high mass can be thrown out at high speed as the rotator material flow, part of material of small mass and powder shape which does not pass through the rotator is used as the peripheral material flow, and evenly distributed along the peripheral to form a material cushion, not only the abrasion of the rotator is reduced, but also the function of stone-beating-stone impact energy is fully played to improve the crushing effect of the stone material
01 Jan 2002