检索结果-内蒙古大学图书馆

Evaluation of manufacturing processes for the production of graded ultrafine grained materials

Procedia Manufacturing 2018年 21卷 45-52页

作者： D. Landgrebe U. Götze M. Bergmann A. Schmidt R. Selbmann Fraunhofer Institute for Machine Tools and Forming Technology Reichenhainer Straße 88 09126 Chemnitz Germany Technische Universität Chemnitz Professorship of Management Accounting and Control 09107 Chemnitz Germany

Scientific research results show that graded ultrafine grained aluminum-based materials offer technical advantages by possible material property improvements (e.g. yield strength, corrosion resistance) especially when applied to heavily stressed components like screws. The commercial screw production is currently conducted without gradation of the semi-finished workpiece. Until now there is no evaluation on whether and under which conditions graded materials (screws) can technically and economically compete with conventional materials. In this paper, an innovative process chain for the production of graded ultrafine grained components is presented and analyzed based on a methodology for an integrated technical-economic evaluation. The evaluation especially of the yield strength of graded materials, energy consumption of the forming steps, energy costs, and revenue effects of improved material properties will outline the technical and economic potential of the technology. Despite higher energy consumptions positive profit effects can be expected due to improved material properties.

关键词： Severe Plastic Deformation aluminium screw technical-economic evaluation process chain evaluation

来源：评论

学校读者我要写书评

暂无评论

Different encapsulation strategies for implanted electronics

引用

Current Directions in Biomedical Engineering 2017年第2期3卷 725-728页

作者： Winkler, Sebastian Edelmann, Jan Welsch, Christine Ruff, Roman Fraunhofer Institute for Machine Tools and Forming Technology Reichenhainer Straße 88 Chemnitz 09126 Germany Fraunhofer Institute for Biomedical Engineering IBMT Ensheimer Strasse 48 66386 St. Ingbert Germany

Recent advancements in implant technology include increasing application of electronic systems in the human body. Hermetic encapsulation of electronic components is necessary, specific implant functions and body environments must be considered. Additional functions such as wireless communication systems require specialized technical solutions for the encapsulation. In this paper 3 different implant strategies based on the material groups silicone, ceramics and titanium alloys are evaluated. With the background of a specific application the requirements for the encapsulation are defined and include the implementation of electrical feedthroughs, wireless communication and wireless energy transfer as well as biomedical specifications such as hermetic sealing, mechanical stability and biocompatibility. The encapsulations are manufactured and qualified experimentally. © 2017 Sebastian Winkler et al., Published by De Gruyter.

关键词： Silicones

来源：评论

学校读者我要写书评

暂无评论

Application of Substructure Techniques to Predict Cutting Stability for Mobile machine tools

引用

Procedia CIRP 2017年 58卷 110-115页

作者： Hendrik Rentzsch Martin Kolouch Matthias Putz Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Str. 88 09126 Chemnitz Germany

Mobile machining solutions use autonomous machining units that can be transported to different part locations, making possible easy maintenance and repair of large industrial equipment. Every new part and location results in different boundary conditions for the mobile machine tool-part system; influencing the dynamics of the combined system and necessitating different strategies for part/machine referencing and clamping. To facilitate efficient mutability and modularity in mobile machining solutions, this paper presents a dynamic substructuring strategy that combines the response characteristics of the mobile machine unit with different base models to obtain the synthesized mobile machine tool dynamic response. Numerical and experimental verification of the approach is provided. Framework presented can also combine measured response of parts for which models may not be available a priori. Methods presented provide experimental guidelines for establishing strategies for planning of machining strategies based on the evaluated dynamics.

关键词： Dynamics machine tool Chatter Substructuring

来源：评论

学校读者我要写书评

暂无评论

Procedure Model for Efficient Simulation Studies which Consider the Flows of Materials and Energy Simultaneously

引用

Procedia CIRP 2017年 61卷 122-127页

作者： Johannes Stoldt Matthias Putz Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 09126 Chemnitz Germany

The premise of this work is that more guidance is required for the application of the simultaneous simulation of material flows and energy flows. This assumption is supported by the findings of a systematic review which showed great diversity in earlier published case studies. Yet, other existing procedure models provide little advice regarding the manifestations of specific details of a simulation study. This paper presents a novel procedure model that is meant to increase the efficiency in simulation projects by providing detailed and consistent guidance for design choices in a simulation study. Selected results of its application are shown exemplarily.

关键词： Simulation Energy efficiency Decision making Procedure model Discrete event simulation

来源：评论

学校读者我要写书评

暂无评论

Predictive Analysis from numerical and experimental data in press hardening

引用

IOP Conference Series: Materials Science and Engineering 2019年第1期651卷

作者： Lars Penter Patrick Link Anke Stoll André Albert Steffen Ihlenfeldt Institute of Mechatronic Engineering TU Dresden Dresden 01062 Germany Fraunhofer Institute for Machine Tools and Forming Technology Chemnitz 09126 Germany

machine learning, big data and deep learning are today's catchphrases for how to improve reliability and productivity of your manufacturing equipment. Production companies implement a large number of sensors to record every activity within their production lines and learn as much as possible about their running processes in order to predict shifting product properties and to prevent stoppage due to failure. The successful application of machine learning algorithms to predict machine and process behavior depends on a reliable and balanced database. Since the foremost goal of every manufacturing business is to make sound parts and to avoid defects, there is a large amount of data available for smoothly running processes but only very little for failure production. One approach to solve this imbalance would be to link the production line data with simulation data. Simulation models allow for computing failure parts with no additional costs and therefore enable the exploration of the entire parameter space. We conducted press-hardening experiments with a variation of process parameters for a structural car body part on the press hardening line at fraunhofer iwu. As an evaluation criterion, we measured the hardness of the final part at critical spots. In order to expand the experimental data, we applied FE simulations to the entire press hardening process chain. The paper explains limitations of the model and elaborates on its parameterization. As a final task, we applied a basic machine-learning algorithm to both experimental and numerical data as well as to their combination in order to evaluate the data space expansion through simulations. The results obtained through machine learning indicate significant differences in the prediction of part quality for solely experimental data and its combination with simulation data. This is especially true for press hardening because of non-linear system behavior and a large amount of uncertain and hard-to-identify parameters. We

关键词：

来源：评论

学校读者我要写书评

暂无评论

Combination of Hot forming with CRP and Rapid Cooling to Obtain Enhanced Formability in Thermomechanical Treatment

Combination of Hot Forming with CRP and Rapid Cooling to Obt...

引用

作者： Birnbaum, Peter Baumann, Markus Kunke, Andreas Kraeusel, Verena Landgrebe, Dirk Technische Universität Chemnitz Chemnitz Germany Fraunhofer Institute for Machine Tools and Forming Technology Chemnitz Germany

In sheet metal forming, rapid cooling of austenitized steel and CRP (cushion-ram pulsation) results in an optimized formability. An analysis is conducted regarding the influence of a stepwise deep drawing process of manganese-boron steel 22MnB5, using an oscillating ram-cushion motion at simultaneous cooling. The stops occurring in stepwise forming provide sufficient time for softening and recovery of forming properties. The microstructure can be adjusted by controlled cooling. In order to examine the newly developed process in more detail, FE simulation is applied. Thus, relevant process and material parameters can be determined. The considered values are required for profound experiments using the forming simulator BAEHR DIL 805 A/D. The softening behavior at defined forming temperatures due to CRP are examined. The experimental results of softening at distinctive temperatures provide a basis for the combined processes of stepwise hot sheet metal forming and simultaneous cooling. © 2017 Materials Research Society.

关键词： Cooling

来源：评论

学校读者我要写书评

暂无评论

Process design for the shaping of sandwich sheets with sensor and actuator functionality

引用

Procedia Engineering 2017年 207卷 872-877页

作者： M. Nestler S. Hensel R. Müller W.-G. Drossel Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Str. 88 09126 Chemnitz Germany

Sandwich materials offer high stiffness in combination with small weight. Functional integration allows for additional active and passive functionalities. The paper deals with sandwich materials with sensor and actuator functionality using integrated piezoceramics. The challenges in production are examined in the paper by experiments and numerical simulation. In order to enable the sandwich material for forming, the adhesive properties are highly significant. An appropriate process chain is developed for manufacturing a semi-finished part with integrated piezoceramics which is suitable for forming.

关键词： deep-drawing finite element analysis layered structures Macro-Fibre-Composite process chain smart structures

来源：评论

学校读者我要写书评

暂无评论

CAD-integrated modelling of Lattice structures for additive manufacturing and property evaluation of generated specimens

CAD-integrated modelling of Lattice structures for additive ...

引用

Materials Science and technology Conference and Exhibition 2017, MS and T 2017

作者： Kordass, R. Koch, P. Toeppel, T. Korn, H. Schoene, C. Mueller, B. Stelzer, R. Fraunhofer Institute for Machine Tools and Forming Technology IWU Noethnitzer Str. 44 Dresden01187 Germany Technical University of Dresden Institute of Machine Elements and Machine Design George-Baehr-Strasse 3c Dresden01069 Germany

ISBN: (纸本)9781510850583

Lattice structures are highly recommended as lightweight components. But until now, parts with lattice structures are mainly used for illustrative purposes. This is because their modelling, dimensioning, and build preparation still remains complex. To simplify this process a CAD-integrated tool is developed. Therein, lattice structures are represented on a parametric level. In the design process the topology of the whole structure as well as single lattice elements can be customized individually. It enables the designer to create fully adapted load carrying components and finally results in lightweight parts, less powder consumption, faster build time, and therefore lower costs during manufacturing. The mechanical properties of the structure are automatically computed by means of FEM. For verification of the mechanical property predictions, tensile tests are performed with Ti-6Al-4V and X3NiCoMoTi18-9-5 steel lattice structures following the design suggestions in draft standard DIN 50099. © Copyright 2017 MS&T17®.

关键词： Poisson ratio

来源：评论

学校读者我要写书评

暂无评论

Biomechanical validation of additively manufactured artificial femoral bones

引用

BMC biomedical engineering 2022年第1期4卷 6页

作者： F Metzner C Neupetsch A Carabello M Pietsch T Wendler W-G Drossel ZESBO Centre for Research on Musculoskeletal Systems Leipzig University Semmelweisstraße 14 04103 Leipzig Germany. florian.metzner@medizin.uni-leipzig.de. Department of Orthopaedics Trauma and Plastic Surgery Leipzig University Leipzig Germany. florian.metzner@medizin.uni-leipzig.de. Department of Orthopaedics Trauma and Plastic Surgery Leipzig University Leipzig Germany. Fraunhofer Institute for Machine Tools and Forming Technology Dresden Germany. Professorship of Adaptronics and Lightweight Design Chemnitz Universtiy of Technology Chemnitz Germany. ZESBO Centre for Research on Musculoskeletal Systems Leipzig University Semmelweisstraße 14 04103 Leipzig Germany.

Replicating the mechanical behavior of human bones, especially cancellous bone tissue, is challenging. Typically, conventional bone models primarily consist of polyurethane foam surrounded by a solid shell. Although nearly isotropic foam components have mechanical properties similar to cancellous bone, they do not represent the anisotropy and inhomogeneity of bone architecture. To consider the architecture of bone, models were developed whose core was additively manufactured based on CT data. This core was subsequently coated with glass fiber composite. Specimens consisting of a gyroid-structure were fabricated using fused filament fabrication (FFF) techniques from different materials and various filler levels. Subsequent compression tests showed good accordance between the mechanical behavior of the printed specimens and human bone. The unidirectional fiberglass composite showed higher strength and stiffness than human cortical bone in 3-point bending tests, with comparable material behaviors being observed. During biomechanical investigation of the entire assembly, femoral prosthetic stems were inserted into both artificial and human bones under controlled conditions, while recording occurring forces and strains. All of the artificial prototypes, made of different materials, showed analogous behavior to human bone. In conclusion, it was shown that low-cost FFF technique can be used to generate valid bone models and selectively modify their properties by changing the infill.

关键词： 3D-printing 3d-printing Additive manufacturing Artificial bone Biomechanics Bone model Femoral Femur Hip

来源：评论

学校读者我要写书评

暂无评论

Automatic Adjustment of Car Body Fixtures Using Artificial Intelligence

引用

Procedia CIRP 2017年 62卷 600-605页

作者： R. Fritzsche A. Richter M. Putz Head of group assembly systems at Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 Chemnitz 09126 Germany Scientific employee at Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 Chemnitz 09126 Germany

In car-body production, the fixtures used for fixing the car-body panels during the joining pro-cesses predominantly consist of rigid constructions that require a time-consuming manual set-up process. To automate the adjustment process and reduce ramp up times, different adjustment modules have been developed at the fraunhofer iwu in order to meet specific requirements. Because of high quality requirements, produced components will be checked against an adjustment database. The exactly positioning for each clamping point will be derived, with the aid of mathematical algorithms and modern methods of artificial intelligence, based on measured values and the knowledge of the template technicians.

关键词： Quality management Body in white Ramp up Artificial intelligence Neuronal network Database

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：