@misc{SchudererRillSchaefferetal., author = {Schuderer, Matthias and Rill, Georg and Schaeffer, Thomas and Schulz, Carsten}, title = {Friction modeling from a practical point of view}, series = {MULTIBODY2023: 11th ECCOMAS Thematic Conference on Multibody Dynamics, Tampa, 24th-28th May 2023}, journal = {MULTIBODY2023: 11th ECCOMAS Thematic Conference on Multibody Dynamics, Tampa, 24th-28th May 2023}, language = {en} } @unpublished{BurgerBartschGradetal., author = {Burger, Moritz and Bartsch, Alexander and Grad, Marius and Esper, Lukas and Schultheiß, Ulrich and Noster, Ulf and Schratzenstaller, Thomas}, title = {Enhancement of laser cut edge quality of ultra-thin titanium grade 2 sheets by applying in-process approach using modulated Yb:YAG continuous wave fibre laser}, doi = {10.21203/rs.3.rs-2520041/v1}, abstract = {Titanium is used in many areas due to its excellent mechanical, biological and corrosion-resistant properties. Implants often have thin and filigree structures, providing an ideal application for laser fine cutting. In literature, the main focus is primarily on investigating and optimizing the parameters for titanium sheet thicknesses greater than 1 mm. Hence, in this study, the basic manufacturing parameters of laser power, cutting speed and laser pulsing of a 200 W modulated fibre laser are investigated for 0.15 mm thick titanium grade 2 sheets. A reproducible, continuous cut could be achieved using 90 W laserpower and 2 cutting-speed. Pulse pause variations between 85-335 μs in 50 μs steps and fixed pulse duration of 50 μs show that a minimum kerf width of 23.4 μm, as well as a minimum cut edge roughness Rz of 3.59 μm, is achieved at the lowest pulse pause. An increase in roughness towards the laser exit side, independent of the laser pulse pause, was found and discussed. The results provide initial process parameters for cutting thin titanium sheets and thus provide the basis for further investigations, such as the influence of cutting gas pressure and composition on the cut edge.}, language = {en} } @unpublished{GradHaagHahnetal., author = {Grad, Marius and Haag, Lydia and Hahn, Konstantin and Schultheiß, Ulrich and Esper, Lukas and Noster, Ulf}, title = {Influence of carbon content on the formation of TiC at diffusion bonded titanium-steel interface}, publisher = {Elsevier}, doi = {10.2139/ssrn.4261928}, abstract = {Hot pressing of pure Ti and various carbon steels in a temperature range of 950 - 1050 °C creates an up to 9 μm thick compound layer of TiC at the Ti/ steel interface. The calculation of the activation energy for layer formation is 126.5 - 136.7 kJ/mol, independent of the steels carbon content. As the carbon content of the steel increases, the layer thickness also increases, which provides enormous potential for the surface modification of Ti/ Ti-alloys.}, language = {en} } @inproceedings{MarinkovicGalkaMeissner, author = {Marinkovic, Minja and Galka, Stefan and Meißner, Sebastian}, title = {Digital Twins for Internal Transport Systems: Use Cases, Functions, and System Architecture}, series = {Proceedings of the 56th Hawaii International Conference on System Sciences: January 3-6, 2023, Maui, Hawaii, USA}, booktitle = {Proceedings of the 56th Hawaii International Conference on System Sciences: January 3-6, 2023, Maui, Hawaii, USA}, publisher = {University of Hawaiʻi at Mānoa}, address = {Honolulu, HI}, isbn = {978-0-9981331-6-4}, pages = {1195 -- 1204}, abstract = {Internal transport systems are an essential part of intralogistics in production and distribution facilities. These are characterized by a variety of technologies as well as a multitude of interactions with other processes, such as warehouse, picking, and production processes. Therefore, resource planning and control of these systems is complex, especially for discontinuous conveyors. In this task, users can be supported by Digital Twins for decision-making, as they are suitable for investigating both future system states and possible actions. However, relevant use cases that are generally applicable across sectors as well as a generic system architecture for Digital Twins for resource planning and process control of in-plant transport systems have not yet been sufficiently investigated. In this paper, use cases are presented, relevant functions defined, and, finally, a generic functional and a logical reference architecture described. This is conducted with the design science in information systems research method together with a Systems Engineering approach. The use cases are determined at industrial partners of the research project TwInTraSys, which explores Digital Twins for the planning and control of internal transport systems. They are generalized and, thus, also applicable to other production and distribution facilities in different sectors. Further, the reference architecture can provide a basis for the successful implementation of the Digital Twin.}, language = {en} } @article{MikhaeilGadererDawoud, author = {Mikhaeil, Makram and Gaderer, Matthias and Dawoud, Belal}, title = {On the application of adsorber plate heat exchangers in thermally driven chillers}, series = {Applied Thermal Engineering}, volume = {220}, journal = {Applied Thermal Engineering}, publisher = {Elsevier}, doi = {10.1016/j.applthermaleng.2022.119713}, abstract = {The effect of both heat and mass transfer characteristic lengths (HTCL, MTCL) of two different adsorber plate heat exchangers (APHE), for application in an adsorption chiller, on the adsorption and desorption kinetics is investigated. Three representative test frames (TF1-TF3) are prepared to examine small-scale adsorbent samples of the microporous silica gel (Siogel of Oker-Chemie, Germany) applying the volumetric large-temperature-jump methodology at different operating conditions. Based on the obtained kinetic data, an analytical model has been developed to predict the specific cooling power (SCP) and the coefficient of performance (COP) of a single-bed adsorption chiller comprising the studied APHEs. It turned out that, within the tested range of HTCL and MTCL, it can be concluded that, the adsorption kinetics are mainly influenced by the MTCL, while the desorption kinetics are dominated by the HTCL of the adsorbent domain. Applying Siogel as loose pellets inside a newly introduced APHE results in of 423.3 and 182.7 W⋅kg-1, at the evaporator temperatures of 15 °C and 5 °C, respectively. Herein, the condenser and adsorber-end temperatures amount to 30 °C and the desorption-end temperature to 90 °C. The corresponding s amount to 0.50 and 0.40, respectively, which represent quite promising results for further design optimizations.}, language = {en} }