Georg Jacobs - Academia.edu (original) (raw)
Papers by Georg Jacobs
Forschung Im Ingenieurwesen-engineering Research, Mar 26, 2021
Wind energy science, Mar 18, 2021
Landtechnik, Dec 23, 2020
Mechanical Systems and Signal Processing
2020 International Conference on Intelligent Engineering and Management (ICIEM), 2020
The objective of this study is to implement an AI-based method to identify parts in (ERP, EDM or)... more The objective of this study is to implement an AI-based method to identify parts in (ERP, EDM or) CAD systems that are especially attractive for Additive Manufacturing (AM). For this purpose, the potentials and limitations of AM are analyzed and formalized. A set of twelve indicators is developed that can be used to assess the complexity of a part as significant parameter for the use of AM. To evaluate these abstract indicators expressing part-complexity, a novel AI-supported procedure is developed. Two classifiers are deduced using a decision tree and an artificial neural network to evaluate and rank the indicators according to their performance. The resulting classifiers reveal that for both AI-methods a part identification on an accuracy level above 90 percent is possible by assessing seven indicators. Both classifiers show prediction accuracies in the same order of magnitude. The resulting AI tool is applied to a practical use case from plant engineering to demonstrate the industrial impact. Several parts of the plant are identified as potential AM parts. The evaluation of manufacturing cost of the most promising part reveal that AM can be beneficial compared to conventional manufacturing.
Due to small batch series or customer orders with specific requirements, costs and especially dev... more Due to small batch series or customer orders with specific requirements, costs and especially development cost are hard to determine. Their impact on the overall costs is enormous and cannot be compensated by current production technologies. To evaluate design efforts, standardized processes are known. Common models as the VDI 2221 are therefore unsuitable due to their generic character of the process steps. They are based on ideal theoretically solutions and do not consider limitations by industrial and organizational constraints. Therefore, a more detailed process is necessary, to make a comparison possible. This paper will show an approach to estimate efforts of a design project as a mathematical function. The process is based on project requirements, the process itself and other related factors which are part of the development. The output is a method for the effort estimation.
This paper reviews the teaching of virtual product development during the past semesters for stud... more This paper reviews the teaching of virtual product development during the past semesters for students of mechanical engineering at RWTH Aachen University. It outlines the specific structure of the course and the exam, and discusses possible impact factors on marks that students achieve. Furthermore, it illustrates challenges in teaching. The so-called digital natives have grown up with computers and digital media. Nevertheless, in education at university level still difficulties using CAD software can be identified.
Tribology International, 2021
Abstract A lubricating film prevents a rolling bearing from high friction and wear by separating ... more Abstract A lubricating film prevents a rolling bearing from high friction and wear by separating the contacting surfaces. In grease lubricated contacts the bled oil induces a hydrodynamic film formation. At high rolling speeds, more bled oil is displaced than replenished, which leads to lubricant starvation. To predict the film formation under starvation, the lubricant supply by replenishment must be determined. However, the effects on oil replenishment are not fully clarified. In particular, the effects of oil wettability as well as the available bled oil amount on the replenishment are not sufficiently investigated. Therefore, in this contribution the oil flow around a rolling point contact is examined under limited oil volume and in dependence of oil wettability, using CFD simulations.
The Proceedings of the JSME international conference on motion and power transmissions, 2017
Umweltverträgliche Tribosysteme, 2010
Die Datenbank enthält die tribologischen und stofflichen Daten, die innerhalb des Sonderforschung... more Die Datenbank enthält die tribologischen und stofflichen Daten, die innerhalb des Sonderforschungsbereichs 442 ermittelt wurden. Sie wird genutzt, um Informationen über die Eigenschaften von Schmierstoffen und Werkstoffverbunden, sowie über Prüfstände und Versuchsergebnisse zu erhalten. Diese Wissensbasis kann dazu beitragen, ökologisch verträgliche Tribosysteme mit Hilfe der Auswerte-Systeme (Module) auszulegen. Dabei handelt es sich um Berechnungswerkzeuge und Expertenwissen z. B. in Bezug auf
Das vordefinierte Ziel des Forschungsvorhabens ist das Aufzeigen von Potenzial und Einsatzgrenzen... more Das vordefinierte Ziel des Forschungsvorhabens ist das Aufzeigen von Potenzial und Einsatzgrenzen schnelldrehender elektrischer Antriebe für mobile Arbeitsmaschinen. Diese Antriebstechnologie wird für den Fahrantrieb eines Ackerschleppers sowie den Bandantrieb einer Straßenfräse umgesetzt. Im Fokus stehen Untersuchungen zu Effizienz, Leistungsdichte und Einsatztauglichkeit.
IEEE Instrumentation & Measurement Magazine, 2014
Forschung im Ingenieurwesen, May 10, 2024
Springer eBooks, Dec 31, 2022
Forschung Im Ingenieurwesen-engineering Research, Dec 7, 2021
The drivetrain as an important part of wind turbines needs to be improved in order to deal with t... more The drivetrain as an important part of wind turbines needs to be improved in order to deal with today's high development and cost pressure. One important step towards enhanced drivetrains is to identify the most suitable concept for a targeted onshore application in an early design stage. With this purpose, a holistic lifecycle system evaluation approach relying on minimum input information is presented. In order to identify a dominant solution, an additive target system is defined taking cost, ecological sustainability, and supplied energy into account. This multi-criteria decision is aggregated by defining a macrosocial evaluation criterion: "drivetrain specific energy supply effort". A physics-and empirically-based model is developed to quantify the targets for different onshore drivetrain concepts. The validity of the model results is shown by a comparison to meta-analysis findings. Being utilized on a drivetrain concept comparison between geared and direct drive the approach's value is showcased. Both concepts score on a comparable level slightly differing in weak and strong wind regimes. An exemplary trade-off between investment-and operational effort shows, that for both concepts the investment effort is higher than the operational. The comparison furthermore shows how robust decision support can be provided by parameter variation and finally it stresses, that the decision maker's preferences need to be incorporated in the decision. Concluding, this analysis shows that physics-and empirically-based model approaches enable holistic wind turbine drivetrain concept comparisons in an early design stage.
Finding an initial shape design for innovative product concepts is one of the most challenging an... more Finding an initial shape design for innovative product concepts is one of the most challenging and most creative parts in product design processes. To support design engineers during that particular phase, knowledge based design automation tools can be used. This paper proposes an enhancement of existing design methodologies in terms of initial shape design of innovative product concepts.The presented approach consolidates PLM and parametric 3D CAD technologies into one integrated method. A concept of parametric working surfaces as an institutionalized feature embedding product lifecycle knowledge is described and briefly demonstrated with a software example. The approach intends to support the product designer with additional information from different company departments as well as giving the designer a tool to explicitly declare the design intent of its design concept in the very early phase of geometric shape definition.
Forschung Im Ingenieurwesen-engineering Research, Mar 30, 2021
Wind turbines (WT) must be further optimized concerning availability and reliability. One of the ... more Wind turbines (WT) must be further optimized concerning availability and reliability. One of the major reasons of WT downtime is the failure of gearbox bearings. Some of these failures occur, due to the ring creep phenomenon, which is mostly detected in the planetary bearings. The ring creep phenomenon describes a relative movement of the outer ring to the planetary gear. In order to improve the understanding of ring creep, the finite element method (FEM) is used to simulate ring creep in planetary gears. First, a sensitivity analysis is carried out on a small bearing size (NU205), to characterize relevant influence parameters for ring creep-considered parameters are teeth module, coefficient of friction, interference fit and normal tooth forces. Secondly, a full-scale planetary bearing (SL185030) of a 1MW WT is simulated and verified with experimental data. Simulative Untersuchung des Ringwanderns an einem Planetenlager eines Planetengetriebes einer Windenergieanlage Zusammenfassung Windenergieanlagen (WEA) müssen hinsichtlich Verfügbarkeit und Zuverlässigkeit weiter optimiert werden. Einer der Hauptgründe für WEA-Ausfälle ist der Ausfall von Getriebelagern. Einige dieser Ausfälle treten aufgrund von Ringwandern auf, welches meist in den Planetenlagern zu beobachten ist. Das Ringwandern beschreibt eine Relativbewegung des Außenrings zum Planetenrad. Um das Verständnis des Ringwanderns zu verbessern, wird die Finite-Elemente-Methode (FEM) zur Simulation des Ringwanderns in Planetengetrieben eingesetzt. Zunächst wird eine Sensitivitätsanalyse an einer kleinen Lagergröße (NU205) durchgeführt, um relevante Einflussparameter für das Ringkriechen zu charakterisierendie berücksichtigten Parameter sind Zahnmodul, Reibungskoeffizient, Presssitz und Zahnnormalkräfte. Zweitens wird ein maßstabsgerechtes Planetenlager (SL185030) einer 1-MW-Anlage simuliert und mit experimentellen Daten verifiziert.
Forschung Im Ingenieurwesen-engineering Research, Mar 26, 2021
Wind energy science, Mar 18, 2021
Landtechnik, Dec 23, 2020
Mechanical Systems and Signal Processing
2020 International Conference on Intelligent Engineering and Management (ICIEM), 2020
The objective of this study is to implement an AI-based method to identify parts in (ERP, EDM or)... more The objective of this study is to implement an AI-based method to identify parts in (ERP, EDM or) CAD systems that are especially attractive for Additive Manufacturing (AM). For this purpose, the potentials and limitations of AM are analyzed and formalized. A set of twelve indicators is developed that can be used to assess the complexity of a part as significant parameter for the use of AM. To evaluate these abstract indicators expressing part-complexity, a novel AI-supported procedure is developed. Two classifiers are deduced using a decision tree and an artificial neural network to evaluate and rank the indicators according to their performance. The resulting classifiers reveal that for both AI-methods a part identification on an accuracy level above 90 percent is possible by assessing seven indicators. Both classifiers show prediction accuracies in the same order of magnitude. The resulting AI tool is applied to a practical use case from plant engineering to demonstrate the industrial impact. Several parts of the plant are identified as potential AM parts. The evaluation of manufacturing cost of the most promising part reveal that AM can be beneficial compared to conventional manufacturing.
Due to small batch series or customer orders with specific requirements, costs and especially dev... more Due to small batch series or customer orders with specific requirements, costs and especially development cost are hard to determine. Their impact on the overall costs is enormous and cannot be compensated by current production technologies. To evaluate design efforts, standardized processes are known. Common models as the VDI 2221 are therefore unsuitable due to their generic character of the process steps. They are based on ideal theoretically solutions and do not consider limitations by industrial and organizational constraints. Therefore, a more detailed process is necessary, to make a comparison possible. This paper will show an approach to estimate efforts of a design project as a mathematical function. The process is based on project requirements, the process itself and other related factors which are part of the development. The output is a method for the effort estimation.
This paper reviews the teaching of virtual product development during the past semesters for stud... more This paper reviews the teaching of virtual product development during the past semesters for students of mechanical engineering at RWTH Aachen University. It outlines the specific structure of the course and the exam, and discusses possible impact factors on marks that students achieve. Furthermore, it illustrates challenges in teaching. The so-called digital natives have grown up with computers and digital media. Nevertheless, in education at university level still difficulties using CAD software can be identified.
Tribology International, 2021
Abstract A lubricating film prevents a rolling bearing from high friction and wear by separating ... more Abstract A lubricating film prevents a rolling bearing from high friction and wear by separating the contacting surfaces. In grease lubricated contacts the bled oil induces a hydrodynamic film formation. At high rolling speeds, more bled oil is displaced than replenished, which leads to lubricant starvation. To predict the film formation under starvation, the lubricant supply by replenishment must be determined. However, the effects on oil replenishment are not fully clarified. In particular, the effects of oil wettability as well as the available bled oil amount on the replenishment are not sufficiently investigated. Therefore, in this contribution the oil flow around a rolling point contact is examined under limited oil volume and in dependence of oil wettability, using CFD simulations.
The Proceedings of the JSME international conference on motion and power transmissions, 2017
Umweltverträgliche Tribosysteme, 2010
Die Datenbank enthält die tribologischen und stofflichen Daten, die innerhalb des Sonderforschung... more Die Datenbank enthält die tribologischen und stofflichen Daten, die innerhalb des Sonderforschungsbereichs 442 ermittelt wurden. Sie wird genutzt, um Informationen über die Eigenschaften von Schmierstoffen und Werkstoffverbunden, sowie über Prüfstände und Versuchsergebnisse zu erhalten. Diese Wissensbasis kann dazu beitragen, ökologisch verträgliche Tribosysteme mit Hilfe der Auswerte-Systeme (Module) auszulegen. Dabei handelt es sich um Berechnungswerkzeuge und Expertenwissen z. B. in Bezug auf
Das vordefinierte Ziel des Forschungsvorhabens ist das Aufzeigen von Potenzial und Einsatzgrenzen... more Das vordefinierte Ziel des Forschungsvorhabens ist das Aufzeigen von Potenzial und Einsatzgrenzen schnelldrehender elektrischer Antriebe für mobile Arbeitsmaschinen. Diese Antriebstechnologie wird für den Fahrantrieb eines Ackerschleppers sowie den Bandantrieb einer Straßenfräse umgesetzt. Im Fokus stehen Untersuchungen zu Effizienz, Leistungsdichte und Einsatztauglichkeit.
IEEE Instrumentation & Measurement Magazine, 2014
Forschung im Ingenieurwesen, May 10, 2024
Springer eBooks, Dec 31, 2022
Forschung Im Ingenieurwesen-engineering Research, Dec 7, 2021
The drivetrain as an important part of wind turbines needs to be improved in order to deal with t... more The drivetrain as an important part of wind turbines needs to be improved in order to deal with today's high development and cost pressure. One important step towards enhanced drivetrains is to identify the most suitable concept for a targeted onshore application in an early design stage. With this purpose, a holistic lifecycle system evaluation approach relying on minimum input information is presented. In order to identify a dominant solution, an additive target system is defined taking cost, ecological sustainability, and supplied energy into account. This multi-criteria decision is aggregated by defining a macrosocial evaluation criterion: "drivetrain specific energy supply effort". A physics-and empirically-based model is developed to quantify the targets for different onshore drivetrain concepts. The validity of the model results is shown by a comparison to meta-analysis findings. Being utilized on a drivetrain concept comparison between geared and direct drive the approach's value is showcased. Both concepts score on a comparable level slightly differing in weak and strong wind regimes. An exemplary trade-off between investment-and operational effort shows, that for both concepts the investment effort is higher than the operational. The comparison furthermore shows how robust decision support can be provided by parameter variation and finally it stresses, that the decision maker's preferences need to be incorporated in the decision. Concluding, this analysis shows that physics-and empirically-based model approaches enable holistic wind turbine drivetrain concept comparisons in an early design stage.
Finding an initial shape design for innovative product concepts is one of the most challenging an... more Finding an initial shape design for innovative product concepts is one of the most challenging and most creative parts in product design processes. To support design engineers during that particular phase, knowledge based design automation tools can be used. This paper proposes an enhancement of existing design methodologies in terms of initial shape design of innovative product concepts.The presented approach consolidates PLM and parametric 3D CAD technologies into one integrated method. A concept of parametric working surfaces as an institutionalized feature embedding product lifecycle knowledge is described and briefly demonstrated with a software example. The approach intends to support the product designer with additional information from different company departments as well as giving the designer a tool to explicitly declare the design intent of its design concept in the very early phase of geometric shape definition.
Forschung Im Ingenieurwesen-engineering Research, Mar 30, 2021
Wind turbines (WT) must be further optimized concerning availability and reliability. One of the ... more Wind turbines (WT) must be further optimized concerning availability and reliability. One of the major reasons of WT downtime is the failure of gearbox bearings. Some of these failures occur, due to the ring creep phenomenon, which is mostly detected in the planetary bearings. The ring creep phenomenon describes a relative movement of the outer ring to the planetary gear. In order to improve the understanding of ring creep, the finite element method (FEM) is used to simulate ring creep in planetary gears. First, a sensitivity analysis is carried out on a small bearing size (NU205), to characterize relevant influence parameters for ring creep-considered parameters are teeth module, coefficient of friction, interference fit and normal tooth forces. Secondly, a full-scale planetary bearing (SL185030) of a 1MW WT is simulated and verified with experimental data. Simulative Untersuchung des Ringwanderns an einem Planetenlager eines Planetengetriebes einer Windenergieanlage Zusammenfassung Windenergieanlagen (WEA) müssen hinsichtlich Verfügbarkeit und Zuverlässigkeit weiter optimiert werden. Einer der Hauptgründe für WEA-Ausfälle ist der Ausfall von Getriebelagern. Einige dieser Ausfälle treten aufgrund von Ringwandern auf, welches meist in den Planetenlagern zu beobachten ist. Das Ringwandern beschreibt eine Relativbewegung des Außenrings zum Planetenrad. Um das Verständnis des Ringwanderns zu verbessern, wird die Finite-Elemente-Methode (FEM) zur Simulation des Ringwanderns in Planetengetrieben eingesetzt. Zunächst wird eine Sensitivitätsanalyse an einer kleinen Lagergröße (NU205) durchgeführt, um relevante Einflussparameter für das Ringkriechen zu charakterisierendie berücksichtigten Parameter sind Zahnmodul, Reibungskoeffizient, Presssitz und Zahnnormalkräfte. Zweitens wird ein maßstabsgerechtes Planetenlager (SL185030) einer 1-MW-Anlage simuliert und mit experimentellen Daten verifiziert.