FG Werkzeugmaschinen und Fertigungstechnik

12 Items

Recent Submissions
Ultrasonic assisted milling of reinforced plastics

Uhlmann, Eckart ; Protz, F. ; Stawiszynski, B. ; Heidler, S. (2017)

The milling of glass and carbon fibre reinforced plastics provides manufacturers from the automotive and aerospace industry with major challenges. The high carbon and glass fibre content increases the risk of insufficient production qualities. The abrasive fibres cause cutting edge rounding which results in the issue that the comparatively thick glass fibre cannot be reliably cut, while the car...

Carbon fibre recycling from milling dust for the application in short fibre reinforced thermoplastics

Uhlmann, Eckart ; Meier, Paul (2017)

A new approach to reuse accruing chips and dust from milling operations of carbon reinforced plastics (CFRP) is studied, show-ing how CFRP milling dust, in comparison to primary and pyrolysed fibres, can find application as a filler material in thermo-plastic granulates. Recent examinations show an overall better handling of milling dust when separating it into different classes of fibre length...

Dynamical fatigue behavior of additive manufactured products for a fundamental life cycle approach

Uhlmann, Eckart ; Fleck, Claudia ; Gerlitzky, Georg ; Faltin, Fabian (2017)

Additive Manufacturing (AM) processes are increasingly integrated into today's value added chains and are prospectively used for batch production. Due to the fact that conventional manufacturing technologies feature design and machining restrictions AM processes offer a nearly restriction free design freedom. This fact could be an answer to the permanent increase in demands of today's products....

Cutting simulation with consideration of the material hardening in the Shear Zone of AISI1045

Uhlmann, E. ; Henze, S. ; Brömmelhoff, K. ; Reimers, W. (2017)

By the use of high energy synchrotron X-ray diffraction it was possible to determine the stress state in the chip formation zone during orthogonal cutting of AISI1045. The analysis of the diffractograms showed a hardening of the material during the movement through the shear zone. For this reason nano indentation experiments on prepared chips have been carried out. With these experiments, the m...

A novel finite element approach to modeling hard turning in due consideration of the viscoplastic asymmetry effect

Uhlmann, Eckart ; Mahnken, Rolf ; Ivanov, Ivan Mitkov ; Cheng, Chun (2015)

A novel material model for strain rate and temperature dependent asymmetric viscoplastic deformation behavior considering transformation induced plasticity (TRIP) as a crucial phenomenon influencing the hard turning process-oriented ductility was developed. Within the framework of viscoplasticity and continuum damage mechanics, the well-established Johnson-Cook flow stress model has been upgrad...

CFD simulation of the Abrasive Flow Machining process

Uhlmann, Eckart ; Schmiedel, Christian ; Wendler, J. (2015)

For the Abrasive Flow Machining (AFM) process, a highly viscous polymeric carrier mixed with abrasive grain is used for deburring, edge rounding and the general improvement of surface quality of workpieces with complex geometries. At present, time-consuming and expensive feasibility studies and parameter analyses are required for each new application. According to a market study of 2012, more t...

Discrete Element modelling of drag finishing

Uhlmann, Eckart ; Eulitz, Alexander ; Dethlefs, Arne (2015)

Drag finishing is a machining process that is used to improve the surface topology of workpieces. Workpieces are moved through a bulk of differently shaped abrasives, the so called media. Material removal is caused by the relative motion between workpiece and media. The material removal rate is mainly depending on the contact intensity between workpiece and media. Up to now there is no viable w...

An automation approach based on workflows and software agents for Industrial Product-Service Systems

Uhlmann, Eckhart ; Gabriel, Christian ; Raue, Niels (2015)

Industrial Product-Service Systems (IPS2) fulfil specific customer needs. This often implies the flexible reaction to changing requirements, impacting the adaption effort for the IPS2 provider. Additionally the modelling of individual business processes for the IPS2 delivery imposes a challenge to the provider. A great variety of process types, ranging from production to maintenance process, ha...

An evaluation of building sets designed for modular machine tool structures to support sustainable manufacturing

Peukert, Bernd ; Saoji, Mihir ; Uhlmann, Eckart (2015)

The modularization of machine tool frames is an approach when designing new machine tool structures in a sustainable context. By integration of microsystem technology and designing lightweight modules, a smart alternative to conventional machine tool frames is developed. In previous studies, this concept has been evaluated along with a compilation of the possible use-case scenarios and the pote...

High Speed Cutting of Carbon Fibre Reinforced Plastics

Uhlmann, Eckart ; Richarz, Sebastian ; Sammler, Fiona ; Hufschmied, Ralph (2016)

The effects of high speed cutting (HSC) on metallic workpiece materials have been widely studied and the benefits are commonly employed in the machining industry. However, in the machining of composite materials, these effects have not yet been a focus of significant research work and core questions such as what impact HSC cutting parameters have on tool wear, process forces and workpiece quali...

Advances in Tool Grinding and Development of End Mills for Machining of Fibre Reinforced Plastics

Uhlmann, Eckart ; Schröer, Nikolas (2015)

The extensive use of lightweight construction materials in the aerospace industry poses a great challenge for tool manufacturers. Materials like carbon fibre reinforced plastics (CFRP) are difficult to machine and therefore put high demands on cutting tools in terms of the cutting material as well as the macro- and microscopic design. In this paper two approaches for the improvement of CFRP mil...

A novel excitation method for pyroshock simulation

Houshmand, Behnam ; Lacher, Alexander ; Juengel, Níkolas ; Prasol, Lukas ; Wagner, Utz von ; Uhlmann, Eckart (2016)

Pyroshocks are structural responses to transient excitation caused by the essential use of pyrotechnic devices in aerospace applications. In order to avoid damage in aerospace structures due to pyroshocks, tests are performed on earth prior to launching space modules. In these tests, explosive loads are often replaced by alternative excitation methods such as hammer pendulums or shakers simulat...