检索结果-内蒙古大学图书馆

2023 IEEE International Magnetic Conference - Short Papers, INTERMAG Short Papers 2023

作者： Thielsch, Juliane Bittner, Florian Drossel, Welf-Guntram Fraunhofer Institute for Machine Tools and Forming Technology Iwu Dresden01187 Germany Chemnitz University of Technology Institute for Machine Tools and Production Processes Chemnitz09126 Germany

ISBN: (纸本)9798350338362

Statistical modelling was successfully applied to Laser Powder Bed Fusion (LPBF) of Nd-Fe-B permanent magnets to identify the potential impact of different process parameters and their interactions on resulting magnetic properties. Process models for the magnetic properties coercivity Hc, remanence Jr as well as for the shape of the demagnetization curve are obtained. The model quality for Hc is excellent (R2 = 0.99). The model for Jr only allows a rough statement on the impact of the LPBF process due to a weaker quality of the model (R2 = 0.77). It will not be possible to maximize Hc and Jr of LPBF manufactured Nd-Fe-B magnets at the same time due to their contrary dependencies on different LPBF parameters. We have predicted an optimized parameter set with a resulting high Hc of 816 kA/m and a maximized Jr of 0.65 T. From these properties and the calculated shape of the demagnetization curve we predict a (BH)max of 60.77 kJ/m3 for a magnet processed on a LPBF machine AconityMINI using MQP™-S powder. © 2023 IEEE.

关键词： Permanent magnets

来源：评论

学校读者我要写书评

暂无评论

Reducing noise and vibrations in wind power plants with DFIG and planetary gearbox through improved rotor current control 56

Reducing noise and vibrations in wind power plants with DFIG...

引用

56th International Conference on Vibroengineering

作者： Windisch, Thomas Hensel, Eric Drossel, Welf-Guntram Fraunhofer-Institute for Machine Tools and Forming Technology IWU Chemnitz Germany

Planetary gears in wind power plants transmit force excitations to the mechanical structure due to alternating tooth meshes. Structure-borne sound is generated and proceeds to tower and nacelle where it is radiated to the environment and may be a noise pollution to residents. In addition, unwanted vibrations can decrease the durability of the gearbox. So far, structural vibrations are being avoided by constructive measures or active absorbers. In contrast to this, our approach is to reduce gear mesh excitations only with the existing electric generator. Therefore, the rotor current control of the machine is enhanced to inject high frequency oscillations so that the wind power generator produces a specific oscillating torque. This anti-noise torque ripple is transmitted via the shaft to the gear stage and minimizes the gear mesh orders so that less force excitations are exposed to the mechanical structure at the bearings. In our knowledge this anti-noise torque approach using the electric generator and its current control is completely new in the field of wind power plants. Simulation is performed using a multi-body-model of the drivetrain to identify an optimal torque oscillation. Afterwards a control circuit model of the generator and the power converter for the rotor circuit is shown. Hence, it is possible to calculate the behavior of the system in high level of detail on the mechanical and the electrical side. Resulting bearing forces are analyzed to prove that excitation can be reduced significantly. No additional hardware, especially no additional actor is needed. Copyright © 2022 Thomas Windisch, et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

关键词： Acoustic noise

来源：评论

学校读者我要写书评

暂无评论

Process concatenation to reduce thermal changes in machine tools

引用

International Journal of Mechatronics and Manufacturing Systems 2022年第2-3期15卷 167-184页

作者： Wenkler, E. Selch, M. Hellmich, A. Ihlenfeldt, S. Institute for Machine Tools and Control Engineering Technische Universität Dresden Dresden01062 Germany Fraunhofer Institute for Machine Tools and Forming Technology IWU Dresden01069 Germany

Thermal effects in machine tools are responsible for a significant amount of produced scrap. Therefore, various approaches have been investigated and applied on machine tools to reduce thermal changes during manufacturing. Most of them target the machine tool and its operational state and can therefore just react to the thermal changes caused by the process. This paper shows how thermal changes can be reduced already in the manufacturing planning stage. With the use of a virtual numerical control (VNC) and loss models, power losses can be estimated, enabling the concatenation of processes to achieve minimal jumps in power loss from one process to another. Copyright © Inderscience Enterprises Ltd.

关键词： Energy efficiency

来源：评论

学校读者我要写书评

暂无评论

Simulation concept for surface designs increasing the coefficient of static friction 22

Simulation concept for surface designs increasing the coeffi...

引用

22nd International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2022

作者： Walther, Franz Wieland, Sebastian Schneider, Jörg Edelmann, Jan Fraunhofer Institute for Machine Tools and Forming Technology IWU Chemnitz Germany

ISBN: (纸本)9781998999118

The objective of the simulation concept for the design of surfaces is the prediction of trends relating to the coefficient of static fric-tion of two friction partners. For the overall consideration, further influencing variables have to be considered, since an exclusive focus on the coefficient of static friction can only inadequately describe the complex tribological behaviour when two surfaces come into contact. To calculate these characteristic values, a multi-stage simulation and calculation approach was developed in which, starting from the generation of experimentally measured or artificially generated surface topography data (stage 1), the true contact area as well as the stress and deformation behaviour when two surfaces come into contact are simulated in contact simula-tions (stage 2). Finally, the coefficient of static friction is calculated based on a micro-roughness model taken from the literature and statistical homogenization (stage 3). The accuracy and validity of the workflow was demonstrated in the experimental valida-tion using ground sample surfaces. Trends with regard to the coefficients of static friction were reliably represented. In addition a method for generating synthetic stochastic surfaces as simulation input was developed. Due to the given comparability with experi-mental surfaces in terms of the geometric properties and the resulting friction behaviour, virtual surfaces can also be used in the future as input of the multistage calculation workflow and applied in simulative parameter studies. © European Society for Precision Engineering and Nanotechnology, Conference Proceedings - 22nd International Conference and Exhibition, EUSPEN 2022. All rights reserved.

关键词： Surface roughness

来源：评论

学校读者我要写书评

暂无评论

OpenMath-RDF: RDF encodings for OpenMath objects and Content Dictionaries 14

OpenMath-RDF: RDF encodings for OpenMath objects and Content...

引用

Joint of the 5th Workshop on Formal Mathematics for Mathematicians, FMM 2019, 2nd Workshop on Formal Verification of Physical Systems, FVPS 2021, 13th Workshop on Mathematical User Interaction, MathUI 2021, 2021 Workshop on Natural Formal Mathematics, NatFoM 2021, and 31st OpenMath Workshops, OM 2021 Doctoral Program and Work in Progress at the 14th Conference on Intelligent Computer Mathematics, CICM-WS 2021

作者： Wenzel, Ken Fraunhofer-Institute for Machine Tools and Forming Technology IWU Chemnitz Germany

This paper presents RDF encodings for OpenMath objects and Content Dictionaries that allow mathematical objects and symbol definitions to be first-class citizens on the Web of Data. © 2022 Copyright for this pape... 详细信息

关键词： Encoding (symbols)

来源：评论

学校读者我要写书评

暂无评论

Intelligent dressing for continuous generating grinding with convolutional neural networks and knowledge distillation 17

Intelligent dressing for continuous generating grinding with...

引用

17th CIRP Conference on Intelligent Computation in Manufacturing Engineering, CIRP ICME 2023

作者： Boesler, Martin Schumann, Marco Klimant, Philipp Dix, Martin Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 Chemnitz09126 Germany Institute for Machine Tools and Production Processes Chemnitz University of Technology Reichenhainer Str. 70 Chemnitz09126 Germany

Continuous generating grinding is a highly productive and precise way to finish hardened gears. However, the dressing of the tool has a huge potential for optimization. Detecting the optimal point to stop the dressing process would save cost and reduce machine downtime. This paper provides a proof of concept of how machine learning models can achieve these goals based on acoustic emission data. Therefore, different ML-Classifiers were trained and compared. Particular emphasis was placed on the robustness of the models. In addition, the trade-off between fast and robust models was examined. © 2024 Elsevier B.V.. All rights reserved.

关键词： Convolutional neural networks

来源：评论

学校读者我要写书评

暂无评论

Design, Fabrication and Characterization of a Novel Variable Stiffness Structure for Soft Continuum Robotics

Design, Fabrication and Characterization of a Novel Variable...

引用

International Joint Conference on Mechanics, Design Engineering and Advanced Manufacturing, JCM 2022

作者： Weisheit, Linda Wockenfuß, Wilhelm Richard Fraunhofer Institute for Machine Tools and Forming Technology IWU Nöthnitzer Straße 44 Dresden01187 Germany

ISBN: (纸本)9783031159275

Soft Robotics made of soft and compliant materials ensure systems with high inherent safety for a safe human-robot collaboration. Thereby current soft robots mostly lack the required stiffness to apply sufficient loads. To ensure inherent safety and at the same time a greater load capacity, structures with adjustable stiffness are required. In this paper, possible approaches for the realization of a switchable stiffness are analyzed and evaluated against the application background of human-oriented soft robotics, which focus mainly on high switching dynamics and high stiffness ratios. A concept for variable stiffness robotic segments based on particle and layer jamming for planar motion is shown, enabling highly dynamic switching between stiff and soft with a bending stiffness ratio K > 100. For this variable stiffness structural component, both the development steps and the characterization methodology are explained. Finally, an outlook on the design of a soft continuum robotic manipulator using three of these variable stiff segments and two tendons for an underactuated motion control of the whole structure is given. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Stiffness

来源：评论

学校读者我要写书评

暂无评论

Experimental setup for long term high-precision static friction tests for clamping systems of rotary tables in cutting machine tools 23

Experimental setup for long term high-precision static frict...

引用

23rd International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2023

作者： Wieland, Sebastian Zschech, Richard Schneider, Jörg Müller, Jens Edelmann, Jan Fraunhofer Institute for Machine Tools and Forming Technology IWU Chemnitz Germany Dresden University of Technology Institute Of Mechatronic Engineering Dresden Germany

ISBN: (纸本)9781998999132

The objective of the scientific investigation is the determination of the coefficient of static friction for clamping systems of rotary tables in cutting machine tools. New developments in this field of research are able to lead to an enhancement in tolerable cutting forces and machine accuracy or to the minimization of the required clamping forces and the constructed space too. In this context the requirement profile of the investigated clamping systems is more than complex. Since they have an immediate influence on the machine accuracy only smallest movements between the friction partners in the range of a few micrometres are tolerable. Furthermore a clamping system needs to withstand more than 100,000 clamping cycles and also braking applications in case of emergency. Against this background an experimental setup consisting of two testing benches was developed. The first testing bench offers the possibility of quick measurements of the coefficient of static friction by a linear movement to investigate a high number of different samples for a selection process. The second test bench in addition offers the possibility of testing the relevant samples by a torsional load for more than 100,000 clamping cycles and in braking applications. In a study the two test benches are validated and compared against each other based on a state of the art clamping system of a tempered steel on the basis of the determined coefficients of static friction. In addition the results of the long term friction experiments and the observed wear are discussed. © 2023 Euspen Headquarters.

关键词： Wear of materials

来源：评论

学校读者我要写书评

暂无评论

Intelligent parameter determination and quality control of an injection molding process 17

Intelligent parameter determination and quality control of a...

引用

17th CIRP Conference on Intelligent Computation in Manufacturing Engineering, CIRP ICME 2023

作者： Nahvi, Sina Schumann, Marco Dix, Martin Klimant, Philipp Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 Chemnitz09126 Germany Institute for Machine Tools and Production Processes Chemnitz University of Technology Reichenhainer Str. 70 Chemnitz09126 Germany

One of the most extensively utilized techniques for material processing is injection molding, which is used to manufacture highly accurate and complex plastic items. In order to produce qualified items and ensure quality of the products, process parameter determination is crucial. We propose and compare two approaches for intelligently determining the parameters and controlling the quality within the injection molding process while aiming towards zero defects. These approaches are combinations of the process model trained using Automated machine Learning (AutoML) with optimization techniques based on Bayesian and genetic algorithms. © 2024 Elsevier B.V.. All rights reserved.

关键词： Injection molding

来源：评论

学校读者我要写书评

暂无评论

Streamlining the development of smart product-service systems

引用

Procedia CIRP 2025年 134卷 699-704页

作者： Anton Mauersberger Heiner Reinhardt Mahtab Mahdaviasl Steffen Ihlenfeldt Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 09126 Chemnitz Germany

The ongoing digitalization of manufacturing leads to the development of smart product-service systems (smart PSSs), where smart, connected products (SCPs) and complementary smart services along with human interaction shape an environment for cooperative business value generation. However, due to the complex nature of smart PSSs, simplified approaches for their strategic development are required. Here, we propose a methodology for the conceptualization and continuous development of smart PSSs. In doing so, we discuss cumulative stages for smart PSSs based on various technological capabilities. Additionally, the time for business value generation in each stage and the need for human interaction are taken into consideration. The introduced methodology is applied to the use case of a multi-sensory tool holder for milling machines.

关键词： Smart PSS Smart service Smart technologies Product-service system Innovation management Sustainable development Lifecycle Decision making Methodology Digital manufacturing system

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：