检索结果-内蒙古大学图书馆

Coupled CFD model of tool environment and workspace to determine the convective heat transfer in jet cooling of milling processes in machine tools

引用

Procedia CIRP 2025年 133卷 280-285页

作者： Steffen Brier Alexander Geist Janine Glänzel Christian Naumann Joachim Regel Martin Dix Steffen Ihlenfeldt Chemnitz University of Technology Professorship Production Systems and Processes Reichenhainer Str. 70 09126 Chemnitz Germany Fraunhofer-Institute for Machine Tools and Forming Technology IWU Reichenhainer Str. 88 09126 Chemnitz Germany Technical University Dresden Institute for Machine Tools Development and Adaptive Controls Helmholtzstraße 10 01069 Dresden Germany

The responsible use of resources is an essential part of the manufacturing of industrial products. This includes the economical use of cooling lubricant and requires precise knowledge of the cooling mechanisms and their effect on the accuracy of the machine tool and thus the thermal error. A temporal and spatial resolution of the dynamic coolant flow near the tool and in the entire workspace in a single model would require a large simulation time. Therefore, a composite model was developed, that consists of a near-tool model and a larger surrounding workspace model. The required static near-tool cooling lubricant distribution is obtained via data discretization methods from a separate static simulation that resolves the turbulence of the cooling lubricant created by the tool rotation. The identified coolant distribution is integrated into a CFD near-tool model (with simplified tool geometry) which is coupled with a surrounding CFD workspace model. The workspace model is thus able to identify the effects of the coolant wetting on the machine surface temperature and finally, using thermo-elastic FEM simulations, on the resulting thermal error. This approach allows the composite model to simulate the entire workspace with reduced simulation effort and map the coolant-influenced heat transfer coefficients on the machine surface.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Challenges and Opportunities in Composite Cathode Production of Polymer-Based Solid-State Batteries 57

Challenges and Opportunities in Composite Cathode Production...

引用

18th IFAC Workshop on Time Delay Systems, TDS 2024

作者： Dhom, Jonas Röß-Ohlenroth, Richard Stumper, Benedikt Berger, Christoph Daub, Rüdiger Fraunhofer Institute for Casting Composite and Processing Technology IGCV Am Technologiezentrum 10 Augsburg86159 Germany Institute for Machine Tools and Industrial Management Technical University of Munich Boltzmannstr. 15 Garching85748 Germany

Higher energy densities and a high level of safety are decisive for the energy storage systems of electric vehicles to satisfy the high range requirements. The polymer-based solid-state battery is a promising technology that stands out due to its high energy density and theoretical safety advantages. Research into this innovative battery technology in Germany and Europe mainly focuses on the laboratory scale. For the production of polymer-based solid-state batteries, there is a lack of accessible information to transfer the laboratory scale to pilot production. Therefore, competence in upscaling the polymer-based composite cathode is essential. The current work investigates the cause-effect relationships of individual production processes of the polymer-based composite cathode in order to establish an in-depth understanding of how they can be scaled. In particular, mixing, coating, and calendering are compared with the corresponding processes of the conventional electrode production of lithium-ion battery cells to identify similarities and differences. The comparison demonstrates that the calendering process is particularly challenging due to the minimization of the porosity of the polymer-based composite cathode. For this reason, the challenges of calendering are discussed in detail. An existing empirical model of the calendering of lithium metal is used to enhance the comprehension of the calendering process. This results in a reduced material consumption and experimental setup time. By using a temporary foil to protect the calender rollers from the high adhesion, polymer-based composite cathodes can be calendered with a conventional roll-to-roll process. The results provide first informations of the scalability of the process of polymer-based composite cathodes from laboratory-based work to a larger scale. © 2024 The Authors.

关键词： Solid-State Batteries

来源：评论

学校读者我要写书评

暂无评论

Assessing the Human Competence and Individual Support Level in Manual Assembly through Cognitive Assistance Systems

引用

Procedia CIRP 2024年 126卷 811-816页

作者： Klaus Fink Anna Ziegler Christian Härdtlein Christoph Berger Rüdiger Daub Fraunhofer Institute for Casting Composite and Processing Technology IGCV Technical University of Munich Institute for Machine Tools and Industrial Management (iwb)

In today’s industrial landscape, production challenges arise from increasing demand for personalized products and demographic changes. Production facilities and employees must be agile and adaptable to changing requirements, while limited automation in multi-variant production elevates the importance of human workers. Cognitive assistance systems, such as digital instructions and pick-by-light systems, can enhance efficiency and reduce errors but should be customized to worker competence levels. This article presents a method for assessing worker competence and individual support using cognitive assistance systems in manual assembly, with an example from fraunhofer IGCV’s "Learning factory for cyber-physical production systems" in Augsburg.

关键词： Manufacturing system Production Human aspect

来源：评论

学校读者我要写书评

暂无评论

Screen printing approach for high throughput and flexible adhesive deposition in graphite bipolar plate production 10

Screen printing approach for high throughput and flexible ad...

引用

10th CIRP Conference on Assembly technology and Systems, CATS 2024

作者： Wagner, Arne Wacker, Christian Dröder, Klaus TU Braunschweig Institute of Machine Tools and Production Technology Langer Kamp 19B Braunschweig38106 Germany Fraunhofer Institute for Surface Engineering and Thin Films IST Riedenkamp 2 Braunschweig38108 Germany

The struggle against climate change necessitates innovative technologies for storing and utilizing renewable energy. Hydrogen is considered a promising solution for harnessing renewable energy in a wide range of applications. In addition to its application as a raw material in the steel and the chemical industry, hydrogen can also be utilized as an energy carrier in conjunction with fuel cells (e.g. with Polymer Electrolyte Membrane Fuel Cells PEMFC) for heavy-duty vehicles, emergency power supplies or the maritime sector. To achieve the required electrical voltages for these applications, several hundred cells are assembled to a stack. A crucial component of an individual cell alongside the Membrane Electrode Assembly (MEA) is the Bipolar Plate (BPP), consisting of two bonded Bipolar Half Plates (BPHP). The BPP enables an inflow of reactive media, the cooling of the cell and is also required for the electrical contacting of the stacked cells as well as the overall mechanical stability. According to previous studies, fully bonded BPPs, especially in the flow field, significantly improve both mechanical and electrical properties of the entire stack. The here presented innovative approach for adhesive deposition aims at bonding graphitic BPHPs to BPPs with a high throughput capability while maintaining high flexibility and process stability. The process is based on the conventional screen printing technique, which in this case is performed without a stencil, allowing for a high flexibility regarding the cell geometry. Furthermore, the range of usable adhesives can be expanded with minor adjustments, allowing for not only paste adhesives but also thermally activated powders. With the presented approach, the adhesive volume can be controlled precisely and applied uniformly by selecting a suitable screen. The feasibility of the approach was tested and initial parameter estimations for potential industrial implementation were determined. © 2024 Elsevier B.V.. All rights r

关键词： Chemical industry

来源：评论

学校读者我要写书评

暂无评论

Assessing Completeness of Production Data in Context of Predictive Quality Applications 2nd

Assessing Completeness of Production Data in Context of Pred...

引用

2nd International Conference on Cyber-Physical Systems and Control, CPS and C 2021

作者： Schlegel, Peter Schmitt, Robert H. Laboratory for Machine Tools and Production Engineering WZL RWTH Aachen University Aachen52074 Germany Fraunhofer Institute for Production Technology IPT Aachen52074 Germany

ISBN: (纸本)9783031208744

Creating a database of high quality is a considerable challenge when building Predictive Quality models for multi-stage production processes. These models aim to make predictions regarding the occurrence of defects based on acquired production data, therefore enabling the user to reduce scrap at an early stage and optimize process parameters. The performance of these models strongly depends on the quality and thus the completeness of the data acquired, which is often not known to the user. Since the completeness depends very much on the expert knowledge of the respective application, a context-specific methodology is needed for its evaluation and visualization. This work proposes such a methodology, which is consisting of four major steps. The first step includes process modeling and collection of data sources, taking into account information classes relevant for data-driven defect prediction. Then, based on the knowledge of process experts, potential quality-influencing variables are identified and weighted. In the third step, a metric is defined based on which the completeness of existing data for individual process steps and information classes is quantified. The fourth step includes the user-friendly visualization of the assessment. The transparency thus created with regard to the completeness of data in the context of Predictive Quality applications allows the identification of data gaps and the derivation of needs for action. This work, therefore, starts even before the actual modeling process and provides a tool for improving the underlying database. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Data completeness Data quality Data suitability Defect prediction Predictive quality Quality control

来源：评论

学校读者我要写书评

暂无评论

Approach to a GPT-based Early Detection Tool to Evaluate Heterogeneous Data Sources and Identify Reconfiguration Needs of SMEs in the Production Sector

引用

Procedia CIRP 2024年 130卷 631-636页

作者： Adrian Jacob Anas Ben Achour Uwe Teicher Steffen Ihlenfeldt Fraunhofer Institute for Machine Tools and Forming Technology IWU Pforzheimer Str. 7a 01189 Dresden Germany TU Dresden Institute of Mechatronic Engineering Helmholtzstr. 7a 01062 Dresden Germany

In the face of a rapidly evolving commercial ecosystem, small and medium-sized enterprises (SMEs) must ensure their process chains are capable of swift reconfiguration to mitigate disruptions from supply chain volatility, regulatory changes, and demand shifts. This study addresses the need for reconfiguration in the context of data-driven opportunities for early identification of reconfiguration needs in SMEs, with a focus on the production sector. We identify a variety of diverse and heterogeneous data sources that are critical for tracking these disruptions, such as public news, economic reports, market analyses, legal documents, and internal corporate records. To make use of these data streams, we propose an innovative early detection tool that employs advanced machine learning techniques and private, locally operated Generative Pretrained Transformers (GPTs). This system is intended to process and analyze the various data formats that SMEs encounter including HTML, PDF and plain text as well as quantitative data. By combining public and company internal data while addressing privacy concerns, the tool aims to provide SMEs with a comprehensive tracking of their commercial environments. The tool also addresses the challenges posed by the limited availability of large datasets within SMEs, which are typically required for effective use of machine learning techniques, allowing for effective operation with smaller datasets. As these technologies continue to advance, their impact across various industries, including legal, manufacturing, and supply chain management, is set to expand significantly. The proposed tool offers SMEs enhanced decision-making, compliance assurance, and the ability to proactively adapt to the unpredictable global business landscape.

关键词： Early Detection Decision support Reconfiguration machine Learning GPT

来源：评论

学校读者我要写书评

暂无评论

Software assisted clamping point classification and position optimization for the efficient flexibilization of carbody fixtures using mathematical geometry-based search algorithms 14

Software assisted clamping point classification and position...

引用

14th CIRP Conference on Intelligent Computation in Manufacturing Engineering, CIRP ICME 2020

作者： Fritzsche, Rayk Schaffrath, Robert Todtermuschke, Marcel Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 Chemnitz09126 Germany

The fraunhofer IWU has been developed specialized clamping robots for production of different car-models on one fixture. One of the challenges with universal clamping of different components is the contact point between part and clamping device. For the optimization of the clamping contours, a software was developed with which the geometries of the clamping points can be automatically analyzed and classified. With target search criteria, the clamping position on the component can be changed so that the clamping contours are geometrically simplified. Thus, a huge reduction in the complexity of the flexible clamping device is possible. © 2021 The Authors. Published by Elsevier B.V.

关键词： Product design

来源：评论

学校读者我要写书评

暂无评论

Ultrasonic assistance to reduce and monitor tool wear in deep drilling 21

Ultrasonic assistance to reduce and monitor tool wear in dee...

引用

21st International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2021

作者： Georgi, Oliver Rüger, Carlo Rentzsch, Hendrik Putz, Matthias Dix, Martin Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Str. 88 Chemnitz09126 Germany

ISBN: (纸本)9780995775190

In deep drilling, the large aspect ratio of hole depth to diameter causes problems in terms of chip formation and removal as well as tool vibrations. In addition, tool wear leads to a deterioration of process properties and decreasing process reliability. Therefore, scientific approaches aim to improve productivity and quality via a reduction of tool wear. Furthermore, methods for monitoring process conditions, specifically known as tool condition monitoring, contribute to an increase in performance. Superimposing ultrasonic vibrations to the conventional process is known as an approach with various potentials like reduced tool wear and burr formation or enhanced chip breaking behaviour. Aiming to realize in-process measurements to identify tool conditions, ultrasonic assistance enables the application of new monitoring techniques. In this context, the paper introduces a new approach to monitor tool wear using characteristic values of the resonant ultrasonic system coupled with the machining process. Experimental investigations considering deep drilling in steel 1.2311 show prove of the positive influence of ultrasonic assistance on the progress of tool wear. Furthermore, in-process measurements demonstrate that the new approach is able to monitor tool wear. © 2021 Proceedings of the 21st International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2021. All rights reserved.

关键词： Aspect ratio

来源：评论

学校读者我要写书评

暂无评论

Experimental validation of characteristic diagram-parameterization for environment-induced thermal interactions on machine tools in a climate chamber 14

Experimental validation of characteristic diagram-parameteri...

引用

14th CIRP Conference on Intelligent Computation in Manufacturing Engineering, CIRP ICME 2020

作者： Kumar, Tharun Suresh Glänzel, Janine Tehel, Robert Putz, Matthias Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Str. 88 Chemnitz09126 Germany

Thermal gradients created by environmental influences on machine tools cause considerable non-linear thermo-elastic deformations whether the machine is in operation or in idle mode. When a machine tool is subjected to changes in environmental influences such as ambient air temperature, velocity or direction, then flow (CFD) simulations are necessary to effectively quantify the thermal behavior between the machine tool surface and the surrounding air. The conventional two-step simulation procedure consisting of coupled CFD and thermo-elastic simulation is highly time-consuming especially when complex geometries are considered. Decoupling of CFD and thermo-elastic simulation can be achieved by introducing a Clustering Algorithm (CA) and Characteristic Diagrams (CDs) within the simulation workflow. Using training data obtained from a limited number of CFD simulations, the CDs can predict the heat transfer coefficients (HTCs) based on the parameterized environmental influences. This paper attempts to validate the experimental temperature and displacement readings obtained at selected positions on a machine tool using a wide range of metrological equipment such thermography camera, temperature and displacement sensors with the decoupling approach based on parameterized CDs. For investigation, the machine tool is positioned in a climate chamber, which facilitates the variation of environmental influences such as ambient temperature, flow velocity and flow direction. Initially, a precise coupled simulation model is created which is later on converted to a decoupled system using parameterized CDs. © 2021 The Authors. Published by Elsevier B.V.

关键词： machine tools

来源：评论

学校读者我要写书评

暂无评论

Novel method for manufacturing herringbone gears by power skiving

引用

Procedia CIRP 2022年 112卷 310-315页

作者： Ruben Bauer Martin Dix Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenainer Str. 88 09126 Chemnitz Germany

Due to the symmetrical flank configuration, herringbone gears have no resulting axial forces and a smaller tooth width than helical gears. Because of existing manufacturing limitations, currently only double helical gears with wide center space or assembled herringbone gears are applied. In the present work, a novel machining method for herringbone gears by power skiving is presented. For this purpose, tool and technology are designed using a mathematical process model and tested subsequently. It is shown that the process can produce the required geometry with significant improvements on productivity and accuracy. Additionally, the unused center area can be eliminated.

关键词： herringbone gears power skiving gear machining process model planetary gears

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：