Univ. Prof. Dr. Ing.

Bergs, Thomas

Filters

5
Reset filters

Settings
Now showing 1 - 5 of 5
  • Publication
    Surrogate Modeling for Multi-Objective Optimization in the High-Precision Production of LiDAR Glass Optics
    ( 2024-04-26)
    Vu, Anh Tuan orcid-logo
    ;
    Paria, Hamidreza
    ;
    Grunwald, Tim
    ;
    Bergs, Thomas
    This study addresses the ever-increasing demands on glass optics for LiDAR systems in autonomous vehicles, highlighting the pivotal role of the recently developed Nonisothermal Glass Molding (NGM) in enabling the mass production of complex and precise glass optics. While NGM promises a significant advancement in cost- and energy-efficient solutions, achieving the requisite shape and form accuracy for high-precision optics remains a persistent challenge. The research focuses on expediting the development phase, presenting a methodology that strategically utilizes a sparse dataset for determining optimized molding parameters with a minimized number of experimental trials. Importantly, our method highlights the exceptional ability of a robust surrogate model to precisely predict the accuracy outputs of glass optics, strongly influenced by numerous input molding parameters of the NGM process. This significance emphasizes the surrogate model, which emerges as a promising alternative to inefficient traditional methods, such as time-consuming experiments or computation-intensive simulations, particularly in the realm of high-precision production for LiDAR glass optics. In contributing to optics manufacturing advancements, this study also aligns with contemporary trends in digitalization and Industry 4.0 within modern optics production, thereby fostering innovation in the automotive industry.
  • Publication
    Assessing the Environmental and Economic Impact of Wire Arc Additive Manufacturing
    ( 2024-04-25)
    Derra, Thomas orcid-logo
    ;
    Belghith, Khouloud
    ;
    Gräfe, Stefan
    ;
    Day, Robin
    ;
    Bergs, Thomas
    Additive Manufacturing (AM) has continuously been integrated in the modern production landscape and complements traditional manufacturing processes by allowing the creation of complex three-dimensional objects through layer-by-layer material deposition. Especially with new design opportunities and short lead times it has significant impact on different industrial sectors such as healthcare, automotive and aerospace. Compared to other AM technologies, Wire Arc Additive Manufacturing (WAAM) has a particularly high material deposition rate and a high degree of flexibility when building large components. Therefore, WAAM has great potential for efficient and resilient production. To quantify this potential the environmental and economic impact must be assessed. The presented study focuses Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) and presents a general methodology for impact analysis as well as a transfer to WAAM. The methodology consists of four steps in accordance with ISO 14044:2006: goal and scope definition, inventory analysis (environmental/economic), environmental impact assessment/cost aggregation, interpretation. For the transfer to WAAM a cradle-to-gate analysis is conducted. The relevant process chain leads from alloy production to the WAAM product manufacturing. The methodology generates relative data, so the final assessment of WAAM must be set into context with alternative processes.
  • Publication
    Precision glass molding process enhancing the expanding of chip on tip endoscopes
    ( 2023-06-07)
    Jiang, Cheng orcid-logo
    ;
    Friedrichs, Marcel
    ;
    Grunwald, Tim
    ;
    Bergs, Thomas
    A new endoscope structure called chip-on-tip is designed to reach both miniaturization and affordability beyond the conventional rigid endoscope. Hence, the precision glass molding process as a replicative manufacturing method can be integrated into the endoscopes production chain and deliver the optics with not only high quality but also reasonable cost under large production volume.
  • Publication
    Tailored melt pool shape by dual laser beam LMD-w process
    ( 2020)
    Gipperich, Marius
    ;
    Riepe, Jan
    ;
    Day, Robin
    ;
    Bergs, Thomas
    Additive Manufacturing (AM) is a fast growing manufacturing market. Laser Metal Deposition (LMD) is a high deposition rate metal AM process mostly used for repair, cladding or manufacturing applications. The two commonly used LMD-processes are powder-based (LMD-p) and wire-based (LMD-w). While LMD-p offers high deposition rates up to 2 kg/h (compared to LMD-w with 1kg/h) the handling of powder in terms of health and safety as well as machine wear become important. Furthermore, the material efficiency (due to overspray) is lower compared to the LMD-w AM-process. This is where LMD-w offers advantages, but advanced concepts to improve the stability of the LMD-w process to the level of LMD-p are needed. In this presentation, an approach is investigated to stabilize the LMD-w process by combining continuous wave (cw) laser and low-power pulsed wave (pw) laser. Calorimeter-like absorption measurements as well as deposition experiments are carried out to understand the physical background of the dual laser process and how this setup helps to stabilize the process. Promising results were achieved showing the possibility to tailor the melt pool height and width by a factor of 1.5-2 and an increase of energy absorption by 20%. This leads to a new perspective for the LMD-w manufacturing process (3D part build up, cladding and repair) in many industry sectors such as mobility, energy and engineering.
  • Publication
    Tailored melt pool shape and temperature distribution by a dual laser beam LMD-w process
    ( 2020)
    Gipperich, Marius
    ;
    Riepe, Jan
    ;
    Day, Robin
    ;
    Bergs, Thomas
    Laser Metal Deposition (LMD) is a high deposition rate metal AM process used for repair, cladding or manufacturing. While wire-based LMD (LMD-w) offers several advantages such as high material efficiency and a safe and simple handling of the wire feedstock, advanced concepts are needed to increase the LMD-w process stability. In this presentation, an approach is investigated to stabilize the LMD-w process by combining a continuous wave (cw) laser and a low-power pulsed wave (pw) laser. Calorimeter-like absorption measurements as well as deposition experiments are carried out to understand the physical background of the dual laser process and how this setup helps to stabilize the process. Promising results were achieved showing the possibility to tailor the melt pool height and width by a factor of 1.5-2 and an increase of energy absorption by 20 %. This offers new perspectives for the LMD-w manufacturing process in many industry sectors.