In manufacturing technologies milkrun and water-spider-based material handling represents up-to-date solutions, especially in the case of just-in-time and just-in-sequence in-plant supply. The objective of this research work is to show how to support the design of milkrun-based in-plant supply with heuristic optimisation in manufacturing processes. This paper proposes a new optimisation approach that can determine the optimal parameters of material handling operations of manufacturing technologies focusing on milkrun-based in-plant supply of manufacturing and assembly cells and lines. After a careful systematic literature review, this paper introduces a structural model to formulate the problem of routing of milkrun trolleys in manufacturing and assembly processes. Next, a potential mathematical model is described. Numerical results demonstrate how the proposed approach supports the decision making process in milkrun design focusing on the optimisation of the required number of milkrun trolleys and the routing of them.
{"title":"A New Design Approach for Milkrun-Based In-Plant Supply in Manufacturing Systems","authors":"T. Bányai, Ádám Francuz","doi":"10.36897/jme/152245","DOIUrl":"https://doi.org/10.36897/jme/152245","url":null,"abstract":"In manufacturing technologies milkrun and water-spider-based material handling represents up-to-date solutions, especially in the case of just-in-time and just-in-sequence in-plant supply. The objective of this research work is to show how to support the design of milkrun-based in-plant supply with heuristic optimisation in manufacturing processes. This paper proposes a new optimisation approach that can determine the optimal parameters of material handling operations of manufacturing technologies focusing on milkrun-based in-plant supply of manufacturing and assembly cells and lines. After a careful systematic literature review, this paper introduces a structural model to formulate the problem of routing of milkrun trolleys in manufacturing and assembly processes. Next, a potential mathematical model is described. Numerical results demonstrate how the proposed approach supports the decision making process in milkrun design focusing on the optimisation of the required number of milkrun trolleys and the routing of them.","PeriodicalId":37821,"journal":{"name":"Journal of Machine Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41585669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Steam turbine technology with enhanced flexibility will continue to participate in electric power supply mixes. Last stage blades secure the reliability of a steam turbine and require high precision manufacturing and assembly. This case study presents a statistical analysis of geometric errors of the throat sizes of the last stage blades in a mid-size steam turbine. A 3D optical scanner is employed to capture detailed geometries of rotor blades and a half of assembled nozzle diaphragm. Unrolled cylinder cross-sections are used to evaluate 2D geometrical features such as blade throats and areas at three different diameters, and the results are compared to intended designs. In addition, linear correlations between the throat size and blade pitch, area and trailing edge thickness are established, and blade throat position shifts are quantified. Such a comprehensive study is presented for the first time, and some useful conclusions can be retrieved from this case study.
{"title":"Analysis of Geometric Errors of Throat Sizes of Last Stage Blades in a Mid-Size Steam Turbine","authors":"P. Eret, M. Hoznedl","doi":"10.36897/jme/151118","DOIUrl":"https://doi.org/10.36897/jme/151118","url":null,"abstract":"Steam turbine technology with enhanced flexibility will continue to participate in electric power supply mixes. Last stage blades secure the reliability of a steam turbine and require high precision manufacturing and assembly. This case study presents a statistical analysis of geometric errors of the throat sizes of the last stage blades in a mid-size steam turbine. A 3D optical scanner is employed to capture detailed geometries of rotor blades and a half of assembled nozzle diaphragm. Unrolled cylinder cross-sections are used to evaluate 2D geometrical features such as blade throats and areas at three different diameters, and the results are compared to intended designs. In addition, linear correlations between the throat size and blade pitch, area and trailing edge thickness are established, and blade throat position shifts are quantified. Such a comprehensive study is presented for the first time, and some useful conclusions can be retrieved from this case study.","PeriodicalId":37821,"journal":{"name":"Journal of Machine Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46301887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Möhring, D. Becker, Clemens Maucher, R. Eisseler, Jonas Ringger
The method of laser powder bed fusion (LPBF) is an additive manufacturing process and allows great freedom of component geometry due to the layer-by-layer structure. The LPBF components are printed on a substrate plate and must be separated from the plate afterwards. Support structures are used to attach LPBF components to the substrate plate and to sustain overhanging parts. The cutting of the components is mainly carried out by means of a sawing process using the support structure. The forces occurring during this process are very challenging because the component has to be cut off without damage or deformation. The present study investigates and discusses the resultant forces and vibrations during the sawing of LPBF components made of titanium alloy Ti6Al4V using two different support structures. The components were arranged on the substrate plate at angles of 0°, 5°, 10°, 15°, 45° and 90° to the direction of primary motion.
{"title":"Influence of the support structure on the bandsawing process when separating LPBF components from the building platform","authors":"H. Möhring, D. Becker, Clemens Maucher, R. Eisseler, Jonas Ringger","doi":"10.36897/jme/151498","DOIUrl":"https://doi.org/10.36897/jme/151498","url":null,"abstract":"The method of laser powder bed fusion (LPBF) is an additive manufacturing process and allows great freedom of component geometry due to the layer-by-layer structure. The LPBF components are printed on a substrate plate and must be separated from the plate afterwards. Support structures are used to attach LPBF components to the substrate plate and to sustain overhanging parts. The cutting of the components is mainly carried out by means of a sawing process using the support structure. The forces occurring during this process are very challenging because the component has to be cut off without damage or deformation. The present study investigates and discusses the resultant forces and vibrations during the sawing of LPBF components made of titanium alloy Ti6Al4V using two different support structures. The components were arranged on the substrate plate at angles of 0°, 5°, 10°, 15°, 45° and 90° to the direction of primary motion.","PeriodicalId":37821,"journal":{"name":"Journal of Machine Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45933621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Additive manufacturing is an essential solution in the production of parts. Model slicing is an important step of the 3D printing process. The slicing of the layers is the core part of the additive manufacturing because it transforms the 3D model to a 2D profile layer for the printer to manufacture. A novel machine architecture deposits with a helical path. The helical architecture provides a continuous rotation that allows printing continuously without any interruption. Therefore there are no more starting and ending point at each layer. This paper proposes a slicing method compatible with this type of machine. Continuous printing is made as a function of z -level, so at each angle of rotation, the level of z will be incremented. Finally, these disks can be combined as one image to be sent to the ink-jet as a continuous printing. To illustrate this novel slicing methodology a model is sliced.
{"title":"A Novel Slicing Strategy for Continuous Printing with a Helix 3D Printer","authors":"tugdual le néel, J. Hascoët, Mesto Tarek","doi":"10.36897/jme/151119","DOIUrl":"https://doi.org/10.36897/jme/151119","url":null,"abstract":"Additive manufacturing is an essential solution in the production of parts. Model slicing is an important step of the 3D printing process. The slicing of the layers is the core part of the additive manufacturing because it transforms the 3D model to a 2D profile layer for the printer to manufacture. A novel machine architecture deposits with a helical path. The helical architecture provides a continuous rotation that allows printing continuously without any interruption. Therefore there are no more starting and ending point at each layer. This paper proposes a slicing method compatible with this type of machine. Continuous printing is made as a function of z -level, so at each angle of rotation, the level of z will be incremented. Finally, these disks can be combined as one image to be sent to the ink-jet as a continuous printing. To illustrate this novel slicing methodology a model is sliced.","PeriodicalId":37821,"journal":{"name":"Journal of Machine Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41658076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Despite a sustainable energy future, steam turbines are requisite for the reliability and security of the electric power supply in many countries. Accurate and precise manufacturing of the steam path is crucial to turbine efficiency. Before entering the rotor blades, the steam must be correctly guided using stationary blading in a diaphragm. Steam turbine diaphragms are complicated components to manufacture, and welding is the most common fabrication method. A case study presented in this paper employs data from a 3D optical scanner for a geometric deviation analysis of the upper half of the diaphragm at two production steps, after complete welding and after final machining. Unrolled cylinder cross-sections at different diameters are used to evaluate the blade throat sizes and positions compared to the nominal geometry. The results indicate significant geometric changes between the two fabrication steps, and several suggestions are put forward for targeted future work.
{"title":"Effect of Manufacturing Processes on Blade Throat Size and Position in a Steam Turbine Diaphragm","authors":"P. Eret, M. Hoznedl","doi":"10.36897/jme/150830","DOIUrl":"https://doi.org/10.36897/jme/150830","url":null,"abstract":"Despite a sustainable energy future, steam turbines are requisite for the reliability and security of the electric power supply in many countries. Accurate and precise manufacturing of the steam path is crucial to turbine efficiency. Before entering the rotor blades, the steam must be correctly guided using stationary blading in a diaphragm. Steam turbine diaphragms are complicated components to manufacture, and welding is the most common fabrication method. A case study presented in this paper employs data from a 3D optical scanner for a geometric deviation analysis of the upper half of the diaphragm at two production steps, after complete welding and after final machining. Unrolled cylinder cross-sections at different diameters are used to evaluate the blade throat sizes and positions compared to the nominal geometry. The results indicate significant geometric changes between the two fabrication steps, and several suggestions are put forward for targeted future work.","PeriodicalId":37821,"journal":{"name":"Journal of Machine Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45652507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present work addresses the topic of die clamping at the forging hammer in the context of the definition of a current requirement profile as well as the evaluation of individual influencing variables on the clamping process. In addition to the presentation of survey results for the requirements profile, the first part focus on the sensible minimization of influencing variables to be investigated and on the verification of a possible evaluation method. Based on this, in the second part exemplary influencing variables on the clamping condition are investigated by means of FEM. Thereby it can be shown by way of example, that the heat flow of the forging process and the friction conditions between the clamping elements have a noteworthy influence on the clamping condition of the dies and that deviations in the clamping force can lead to significant damage.
{"title":"Characterization of tool clamping conditions in forging hammers","authors":"Nicole J. Wagner, R. Tehel, R. Kurth","doi":"10.36897/jme/150220","DOIUrl":"https://doi.org/10.36897/jme/150220","url":null,"abstract":"The present work addresses the topic of die clamping at the forging hammer in the context of the definition of a current requirement profile as well as the evaluation of individual influencing variables on the clamping process. In addition to the presentation of survey results for the requirements profile, the first part focus on the sensible minimization of influencing variables to be investigated and on the verification of a possible evaluation method. Based on this, in the second part exemplary influencing variables on the clamping condition are investigated by means of FEM. Thereby it can be shown by way of example, that the heat flow of the forging process and the friction conditions between the clamping elements have a noteworthy influence on the clamping condition of the dies and that deviations in the clamping force can lead to significant damage.","PeriodicalId":37821,"journal":{"name":"Journal of Machine Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46570061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As a multi-axis metal cutting operation, turn-milling has the combined characteristics of conventional turning and milling operations involving rotating workpiece and milling tool with linear feed motion in the workpiece axis direction. Although turn-milling offers many advantages in machining complex and hard-to-cut materials due to its flexible kinematics, the process presents specific challenges. The main objective of this paper is to present an overview of turn-milling operations from different perspectives. In this regard, first, the advantages of turn-milling in terms of tool life are presented. An analytical approach is given based on process kinematics to achieve better surface quality and productivity simultaneously. Additionally, the uncut chip geometry and the cutting force models are presented with experimental verification.
{"title":"Improved Machining Performance Through Turn-Milling","authors":"K. Berenji, E. Budak","doi":"10.36897/jme/150495","DOIUrl":"https://doi.org/10.36897/jme/150495","url":null,"abstract":"As a multi-axis metal cutting operation, turn-milling has the combined characteristics of conventional turning and milling operations involving rotating workpiece and milling tool with linear feed motion in the workpiece axis direction. Although turn-milling offers many advantages in machining complex and hard-to-cut materials due to its flexible kinematics, the process presents specific challenges. The main objective of this paper is to present an overview of turn-milling operations from different perspectives. In this regard, first, the advantages of turn-milling in terms of tool life are presented. An analytical approach is given based on process kinematics to achieve better surface quality and productivity simultaneously. Additionally, the uncut chip geometry and the cutting force models are presented with experimental verification.","PeriodicalId":37821,"journal":{"name":"Journal of Machine Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42904273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper fundamental information on the influence of the real machined surfaces generated by different machining processes on the fatigue life of machine parts are presented. In the first part the various approaches for the assessment of the stress concentration factor and the correction of a fatigue life limit are discussed. In the second part the results of standard fatigue tests are compared with computed data and predictions using FEM based simulations. The effect of surface discontinues (valleys) in the real surface profiles is related to engineered parts made of different materials including steels, aluminium alloys, aerospace alloys and composites.
{"title":"Influence of Different Machining Processes on Fatigue life Performance of Engineered Surfaces: a Short Review","authors":"W. Grzesik","doi":"10.36897/jme/150322","DOIUrl":"https://doi.org/10.36897/jme/150322","url":null,"abstract":"In this paper fundamental information on the influence of the real machined surfaces generated by different machining processes on the fatigue life of machine parts are presented. In the first part the various approaches for the assessment of the stress concentration factor and the correction of a fatigue life limit are discussed. In the second part the results of standard fatigue tests are compared with computed data and predictions using FEM based simulations. The effect of surface discontinues (valleys) in the real surface profiles is related to engineered parts made of different materials including steels, aluminium alloys, aerospace alloys and composites.","PeriodicalId":37821,"journal":{"name":"Journal of Machine Engineering","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41455895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Building repositories of data relevant for enterprise operations requires harmonization of formats and semantics. OPC UA’s nodes-and-references data model shares basic elements with well-established semantic modeling technologies like RDF. This paper suggests the use of transformed OPC UA information models on the higher level of Enterprise Knowledge Graphs. It proposes good practice to integrate the separate domains by representing OPC UA servers as RDF-graphs and subsequently attaching them to Digital Twins embedded in Enterprise Knowledge Graph structures. The developed practice is implemented, applied to combine a server’s structure with an existing knowledge graph containing an Asset Administration Shell and released open source.
{"title":"Integration of OPC UA Information Models into Enterprise Knowledge Graphs","authors":"Arno Weiss, S. Ihlenfeldt","doi":"10.36897/jme/150008","DOIUrl":"https://doi.org/10.36897/jme/150008","url":null,"abstract":"Building repositories of data relevant for enterprise operations requires harmonization of formats and semantics. OPC UA’s nodes-and-references data model shares basic elements with well-established semantic modeling technologies like RDF. This paper suggests the use of transformed OPC UA information models on the higher level of Enterprise Knowledge Graphs. It proposes good practice to integrate the separate domains by representing OPC UA servers as RDF-graphs and subsequently attaching them to Digital Twins embedded in Enterprise Knowledge Graph structures. The developed practice is implemented, applied to combine a server’s structure with an existing knowledge graph containing an Asset Administration Shell and released open source.","PeriodicalId":37821,"journal":{"name":"Journal of Machine Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45300690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Ramsauer, Ralf Oswald, Paul Schörghofer, Norbert Leder, T. Schmitz, F. Bleicher
Brush deburring requires consistent contact pressure between brush and workpiece. Automating adjustments to control contact pressure has proven difficult, as the sensors available in machine tools are usually not suitable to observe the small amplitude signals caused by this low force process. Additionally, both the power consumption and the vibration signal caused by the process strongly depend on the workpiece surface features. This paper describes a test setup using an instrumented tool holder and presents the corresponding measurement results, aiming to quantify the axial feed of the brush. It also discusses the interpretation of different signal components and provides an outlook on the utilization of the data for tool wear estimation.
{"title":"Primary Testing of an Instrumented Tool Holder for Brush Deburring of Milled Workpieces","authors":"C. Ramsauer, Ralf Oswald, Paul Schörghofer, Norbert Leder, T. Schmitz, F. Bleicher","doi":"10.36897/jme/149782","DOIUrl":"https://doi.org/10.36897/jme/149782","url":null,"abstract":"Brush deburring requires consistent contact pressure between brush and workpiece. Automating adjustments to control contact pressure has proven difficult, as the sensors available in machine tools are usually not suitable to observe the small amplitude signals caused by this low force process. Additionally, both the power consumption and the vibration signal caused by the process strongly depend on the workpiece surface features. This paper describes a test setup using an instrumented tool holder and presents the corresponding measurement results, aiming to quantify the axial feed of the brush. It also discusses the interpretation of different signal components and provides an outlook on the utilization of the data for tool wear estimation.","PeriodicalId":37821,"journal":{"name":"Journal of Machine Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45168836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}