@inproceedings{SchmailzlHierl, author = {Schmailzl, Anton and Hierl, Stefan}, title = {Thermo-mechanische Struktursimulation mit ANSYS Workbench 14.0 am Beispiel des Laser-Durchstrahlschweißens}, series = {ANSYS Conference \& 31st CADFEM Users' Meeting - ACUM, June 19-21, Mannheim}, booktitle = {ANSYS Conference \& 31st CADFEM Users' Meeting - ACUM, June 19-21, Mannheim}, editor = {CADFEM GmbH, and ANSYS Germany GmbH,}, address = {Grafing bei M{\"u}nchen, Darmstadt}, pages = {1 -- 16}, language = {de} } @techreport{TalbotHierlSchmailzl, author = {Talbot, Sebastian and Hierl, Stefan and Schmailzl, Anton}, title = {Thermische FEM-Simulation des Laser-Durchstrahlschweißens}, series = {Forschungsbericht 2013}, journal = {Forschungsbericht 2013}, editor = {Baier, Wolfgang}, address = {Kiel}, organization = {Ostbayerische Technische Hochschule Regensburg}, pages = {45 -- 46}, language = {de} } @inproceedings{PreischlSchmailzlHierl, author = {Preischl, Antonius and Schmailzl, Anton and Hierl, Stefan}, title = {Experimental study to evaluate the process window for laser transmission welding of plastics}, series = {Applied Research Conference 2014 - ARC 2014, 5th July 2014, Ingolstadt}, booktitle = {Applied Research Conference 2014 - ARC 2014, 5th July 2014, Ingolstadt}, editor = {Ziemann, Olaf and Mottok, J{\"u}rgen and Pforr, Johannes}, publisher = {Shaker}, address = {Aachen}, pages = {517 -- 522}, language = {en} } @incollection{SchmailzlHierl, author = {Schmailzl, Anton and Hierl, Stefan}, title = {Online-Prozess{\"u}berwachung beim Quasi-Simultanen Laser-Durchstrahlschweißen von Kunststoffen}, series = {Young Professionals - Jugend forscht und schweisst}, booktitle = {Young Professionals - Jugend forscht und schweisst}, editor = {GSI Niederlassung SLV M{\"u}nchen,}, pages = {1 -- 7}, language = {de} } @article{StegerDostalekSchmailzletal., author = {Steger, Sebastian and Dostalek, Michael and Schmailzl, Anton and Hierl, Stefan}, title = {Fehlstellen sicher erkennen}, series = {Kunststoffe}, volume = {105}, journal = {Kunststoffe}, number = {12}, pages = {55 -- 58}, language = {de} } @inproceedings{Hierl, author = {Hierl, Stefan}, title = {Laser Transmission Welding of Plastics}, series = {15th International Materials Symposium - IMSP'2014, Denizli, 2014}, booktitle = {15th International Materials Symposium - IMSP'2014, Denizli, 2014}, editor = {Meran, Cemal}, pages = {1084 -- 1093}, language = {en} } @incollection{SchmailzlHuentelmannLooseetal., author = {Schmailzl, Anton and H{\"u}ntelmann, Sven and Loose, Tobias and K{\"a}sbauer, Johannes and Maiwald, Frederik and Hierl, Stefan}, title = {Potentials of the ALE-Method for Modeling Plastics Welding Processes, in Particular for the Quasi-Simultaneous Laser Transmission Welding}, series = {Mathematical Modelling of Weld Phenomena 12}, booktitle = {Mathematical Modelling of Weld Phenomena 12}, editor = {Sommitsch, Christof and Enzinger, Norbert and Mayr, Peter}, publisher = {Verlag der Technischen Universit{\"a}t Graz}, address = {Graz}, doi = {10.3217/978-3-85125-615-4-51}, pages = {965 -- 975}, abstract = {The Arbitrary-Lagrangian-Eulerian-Method (ALE-Method) offers the possibility to model the quasi-simultaneous laser transmission welding of plastics, in which a squeeze-flow of molten plastic occurs. It is of great interest to get a deeper understanding of the fluid-structure-interactions in the welding zone, since the occurring squeeze-flow transports heated material out of the joining zone, causinga temperature decrease inside.In addition, the numerical modelling offers the possibility to investigate the flow conditions in the joining zone. The aim of this article is to show the potentials of the ALE-Method to simulatethe quasi-simultaneous laser transmission welding with the commercially available software LS-DYNA. The central challenge is to realize a bi-directionalthermo-mechanically coupled simulation,which considers the comparatively high thermal expansion and calculates the interactions of solid and melted plastic correctly. Finally, the potentials of the ALE element formulations for the mathematical description of welding processesare shown, especially for those with a squeeze-flow.}, language = {en} } @inproceedings{SchmailzlHierlSchmidt, author = {Schmailzl, Anton and Hierl, Stefan and Schmidt, Michael}, title = {Gap-Bridging during Quasi-Simultaneous Laser Transmission Welding}, series = {Physics Procedia}, volume = {83}, booktitle = {Physics Procedia}, editor = {Schmidt, Michael}, publisher = {Elsevier}, address = {Amsterdam [u.a.]}, issn = {1875-3892}, doi = {10.1016/j.phpro.2016.08.113}, pages = {1073 -- 1082}, abstract = {Tightness is often the main requirement for quasi-simultaneous laser transmission welds. However, remaining gaps cannot be detected by the used set-path monitoring. By using a pyrometer in combination with a 3D-scanner, weld seam interruptions can be localized precisely while welding, due to temperature deviations along the weld contour. To analyze the temperature signal in correlation to the progress of gap-bridging, T-joint samples with predefined gaps are welded. The set-path is measured synchronously. Additionally, the temperature distribution and the influence of the thermal expansion of the polymers are studied by a thermo-mechanical FEM-process simulation. On top of that, the melt blow-out of the welded samples is analyzed using μCT-measurements. The experiments have shown that closing of a gap can be identified reliably by the temperature signal and that the squeezed melt flow into the gap and the thermal expansion in the gap zone accelerates gap-bridging. Furthermore the inserted heat can be adapted in the fault zone, in order to avoid thermal damage.}, language = {en} } @inproceedings{SchmailzlAmannGlockneretal., author = {Schmailzl, Anton and Amann, Thomas and Glockner, Markus and Fandanelli, Martin and Wagner, Marcus and Hierl, Stefan}, title = {Finite element analysis of thermoplastic probes under tensile load using ls-dyna compared to ansys workbench 14 in correlation to experimental investigations}, series = {ANSYS Conference \& 30th CADFEM Users' Meeting - ACUM, 24.-26- Oktober 2012, Kassel}, booktitle = {ANSYS Conference \& 30th CADFEM Users' Meeting - ACUM, 24.-26- Oktober 2012, Kassel}, editor = {CADFEM GmbH, and ANSYS Germany GmbH,}, address = {Grafing bei M{\"u}nchen}, pages = {1 -- 10}, abstract = {Joining thermoplastic requisitions is a popular technique to build sophisticated plastic applications. Therefore the laser-transmission welding process is used to join thermoplastic polymers in visible regions. The clamping force in this case plays a decisive role when it comes to the weld quality. Simulating the clamping pressure with finite element techniques is therefore highly attractive to understand the principal of the process. Thermoplastic polymers under tensile load often show a brittle behavior coupled with softening. Simulating such materials is quite difficult for FEM programs. In this case a finite element study of the tensile test in LS-DYNA and ANSYS Wb 14 with respect to the material models was analysed. The experimental data get validated in comparison with the FEM solution for a tensile test. The material models and the problems in simulating softening behavior for thermoplastic polymers were discussed}, language = {en} } @inproceedings{SchmailzlQuandtSchmidtetal., author = {Schmailzl, Anton and Quandt, Benjamin and Schmidt, Michael and Hierl, Stefan}, title = {In-Situ Process Monitoring during Laser Transmission Welding of PA6-GF30}, series = {Procedia CIRP}, volume = {74}, booktitle = {Procedia CIRP}, doi = {10.1016/j.procir.2018.08.131}, pages = {524 -- 527}, abstract = {Quasi-simultaneous laser transmission welding is preferably used for packaging sensors and electronics. In order to protect the components from moisture, a hermetic encapsulation is needed. However, local weld seam interruptions cannot be identified with the commonly used set-path monitoring. By using a pyrometer, coaxially integrated into a 3D-scanner, gaps between the joining partners can be allocated on basis of the measured temperature. However, the scattering of the heat radiation, especially caused by the fiber reinforcement of the plastics, leads to a reduction of the accessible heat radiation, which makes the identification of gaps considerably more difficult. The herein used experimental setup is characterized by a small detection spot and only by a slight weakening of the heat radiation inside the scanner. Hence, for welding PA6-GF30, the detection of small sized gaps is possible, even if a glass fiber content of 30 percent (wt.) and a weld seam width with approximately 1 mm are given.}, language = {en} } @article{SchmailzlHierlSiebenetal., author = {Schmailzl, Anton and Hierl, Stefan and Sieben, Manuel and Brunnecker, Frank}, title = {Optimierung der Spanndruckverteilung beim Laserdurchstrahlschweißen komplexer Bauteile mittels FE-Berechnung}, series = {JOINING PLASTICS}, volume = {7}, journal = {JOINING PLASTICS}, number = {1}, pages = {30 -- 34}, language = {de} } @inproceedings{SchmailzlHierl, author = {Schmailzl, Anton and Hierl, Stefan}, title = {Online-process monitoring of laser transmission welding for polymers}, series = {Applied Research Conference 2013, ARC 2013 ; 17th and 18th October 2013, Deggendorf}, booktitle = {Applied Research Conference 2013, ARC 2013 ; 17th and 18th October 2013, Deggendorf}, editor = {Ziemann, Olaf and Bogner, Werner and Mottok, J{\"u}rgen}, publisher = {Shaker}, address = {Aachen}, pages = {374 -- 378}, language = {en} } @article{MaiwaldEnglmaierHierl, author = {Maiwald, Frederik and Englmaier, Stephan and Hierl, Stefan}, title = {Online pyrometry for weld seam localization in absorber-free laser transmission welding of transparent polymers}, series = {Journal of Laser Micro/Nanoengineering}, volume = {Vol. 16}, journal = {Journal of Laser Micro/Nanoengineering}, number = {1}, publisher = {Japan Laser Processing Society}, issn = {1880-0688}, doi = {10.2961/jlmn.2021.01.2002}, pages = {8 -- 13}, abstract = {Production of optical and medical devices makes high demands on cleanliness, precision, visual appearance and reliability. Advantages of laser transmission welding - contactless input of energy, high precision, no adhesives and no particle formation - can be fully exploited for this use. For absorber-free welding, lasers emitting in the polymers' intrinsic absorption spectrum between 1.6 μm and 2 μm are used. Focusing the laser beam with high NA provides large intensity gradients inside the specimen and enables selective fusing of the joining zone without affecting the surface. Since a molten upper surface leads to visible and palpable irregularities and causes warpage, the verticalexpansion of the weld seam is crucial. To meet the high quality and reliability required in the medical and optical industry, online monitoring of the seam is necessary. The aim of this work is the localization and evaluation of the weld seam using pyrometry. First, the emitted thermal radiation is computed, enabling signal analysis regarding origin and spectrum. Thus, assessment of measurement spectrum and forecast of the signal in dependence on seam shape and position is possible. Finally, welding tests with Topas 8007-04 are performed at 200 mm/s feed rate and monitored with 100 kHz. The comparison of tracked data with thin-cuts demonstrates that weld seam localization by pyrometry is possible, enabling online assessment of the process.}, subject = {Laserdurchstrahlschweissen}, language = {en} } @inproceedings{MaiwaldEnglmaierHierl, author = {Maiwald, Frederik and Englmaier, Stephan and Hierl, Stefan}, title = {Online pyrometry for weld seam localization in absorber-free laser transmission welding of transparent polymers}, series = {21st International Symposium on Laser Precision Microfabrication: Dresden, 26.06.2020}, booktitle = {21st International Symposium on Laser Precision Microfabrication: Dresden, 26.06.2020}, publisher = {Japan Laser Processing Society}, abstract = {Optical and medical devices made of transparent polymers are gaining popularity because of its cost advantages. The manufacturing technology must be able to meet the high demands of these applications. Advantages of laser transmission welding - contactless input of energy, precision, no adhesives and no particle formation - can be exploited here. For absorber-free welding, lasers emitting in the polymers' intrinsic absorption spectrum are used. Focusing the laser beam with high NA enables selective fusing of the joining zone. Since a molten upper surface leads to visible and palpable irregularities, the lateral expansion of the weld seam is monitored in this work. Welding tests with 1 mm thick plates of COC are performed and monitored by pyrometry. Distances between seam and surface measured in thin cuts and are compared with the pyrometer signal. This shows that the localization of the weld seam is possible and proper and faulty parts can be distinguished by pyrometry.}, subject = {Laserdurchstrahlschweissen}, language = {en} } @article{MaiwaldHierl, author = {Maiwald, Frederik and Hierl, Stefan}, title = {Pyrometerbasierte Prozess{\"u}berwachung beim Laserkunststoffschweißen}, series = {Photonik}, journal = {Photonik}, number = {52}, publisher = {AT-Fachverl.}, address = {Fellbach}, pages = {22 -- 25}, subject = {Laserschweissen}, language = {de} } @inproceedings{KaesbauerSchmailzlPrehmetal., author = {K{\"a}sbauer, Johannes and Schmailzl, Anton and Prehm, Jens and Loose, Tobias and Hierl, Stefan}, title = {Simulation of Quasi-Simultaneous Laser Transmission Welding of Plastics}, series = {Procedia CIRP}, volume = {94}, booktitle = {Procedia CIRP}, publisher = {Elsevier}, doi = {10.1016/j.procir.2020.09.136}, pages = {737 -- 741}, abstract = {Thermo-mechanical simulation offers great opportunities to optimize welding processes of plastics. For realistic simulation, the temperature dependent mechanical properties need to be implemented from ambient temperature to temperatures above the flow temperature. Standard test methods are insufficient for characterization in the entire temperature range because close to the flow temperature the material is too soft for tensile tests and too stiff for rheometry. Therefore, an optimization strategy is developed, that determines unknown material parameters by testing in welding simulations. The unknown parameters are iteratively adjusted to minimize the mismatch between computed and measured set-paths. Thus, important process characteristics are calculated realistically, enabling the computer aided assessment of the weld quality.}, subject = {Kunststoffschweißen}, language = {en} } @inproceedings{MaiwaldEnglmaierHierl, author = {Maiwald, Frederik and Englmaier, Stephan and Hierl, Stefan}, title = {Absorber-free Laser Transmission Welding of Transparent Polymers using Fixed Focus Optics and 3D Laser Scanner}, series = {Procedia CIRP}, volume = {94}, booktitle = {Procedia CIRP}, publisher = {Elsevier}, doi = {10.1016/j.procir.2020.09.117}, pages = {686 -- 690}, abstract = {Laser transmission welding is a well-known joining technology for thermoplastics, providing reliable and hermetical sealing without adhesives or particle formation. The main advantages of laser-based energy input - high precision, no additional adhesive and no particle emission - are essential for medical and optical applications. To obtain sufficient absorption in visually transparent polymers, thulium fibre lasers emitting in the polymers' intrinsic absorption spectrum are used. Optics with high numerical aperture provide large intensity gradients inside the specimen, enabling selective fusing in the joining zone. Although the basic feasibility has already been demonstrated, the welding process lacks stability and productivity. Aim of this work is the determination of optimized settings for a fast and reliable welding process. Thus, the interplay of process parameters as well as their impact on the seam are analysed by thermal simulations. Calculated settings are verified by welding tests with COC, PA6 and PETG, using a fixed-focus optics and a 3D laser scanner with up to 200 mm/s feed rate.}, language = {en} } @article{SchmailzlKaesbauerMartanetal., author = {Schmailzl, Anton and K{\"a}sbauer, Johannes and Martan, Jiř{\´i} and Honnerov{\´a}, Petra and Sch{\"a}fer, Felix and Fichtl, Maximilian and Lehrer, Tobias and Pruš{\´a}kov{\´a}, L. and Tesař, Jiř{\´i} and Sk{\´a}la, J. and Honner, Milan and Hierl, Stefan}, title = {Measurement of Core Temperature through Semi-Transparent Polyamide 6 using Scanner-Integrated Pyrometer in Laser Welding}, series = {International Journal of Heat and Mass Transfer}, volume = {146}, journal = {International Journal of Heat and Mass Transfer}, number = {January}, publisher = {Elsevier}, doi = {10.1016/j.ijheatmasstransfer.2019.118814}, abstract = {Predicting the core temperature during welding is an ambitious aim in many research works. In this work, a 3D-scanner with integrated pyrometer is characterized and used to measure the temperature during quasi-simultaneous laser transmission welding of polyamide 6. However, due to welding in an overlap configuration, the heat radiation emitted from the joining zone of a laser transmission weld has to pass through the upper polymer, which is itself a semi-transparent emitter. Therefore, the spectral filtering of the heat radiation in the upper polymer is taken into account by calibrating the pyrometer for the measurement task. Thermal process simulations are performed to compare the temperature field with the measured temperature signal. The absorption coefficients of the polymers are measured, in order to get precise results from the computation. The temperature signals during welding are in good agreement with the computed mean temperature inside the detection spot, located in the joining area. This is also true for varying laser power, laser beam diameter and the carbon black content in the lower polymer. Both, the computed mean temperature and the temperature signal are representing the core temperature. In order to evaluate the spatial sensitivity of the measurement system, the emitted heat radiation from both polymers is calculated on basis of the computed temperature field. Hereby it is found, that more than 90 percent of the detected heat radiation comes from the joining area, which is a crucial information for contact-free temperature measurement tasks on semi-transparent polymers.}, language = {en} } @inproceedings{SchmailzlQuandtHierletal., author = {Schmailzl, Anton and Quandt, Benjamin and Hierl, Stefan and Schmidt, Michael}, title = {Correlation between Joint Strength and Process Temperature in Quasi-Simultaneous Laser Transmission Welding of Polyamide 6}, series = {Proceedings of LiM2019 - Lasers in Manufacturing (23 June 2019, Munich)}, booktitle = {Proceedings of LiM2019 - Lasers in Manufacturing (23 June 2019, Munich)}, publisher = {Wissenschaftliche Gesellschaft Lasertechnik e.V.}, pages = {1 -- 10}, abstract = {The joint strength is gaining importance in quasi -simultaneous laser transmission welds, especially in structural components. A correlation between the joint strength and a process characteristic is a basic requirement for selecting the best process parameter setting. In this work, the temperature is measured during welding polyamide 6 by using a scanner-integrated pyrometer with an InGaAs-detector. The filtering of the heat radiation in the upper joining partner is taken into account by calibrating the mea surement system. By this, the measured temperature signal represents the temperature in the joining zone. A correlation is found between the measured temperature and the resulting joint strength. Moreover, high joint strengths are also seen for welds with short welding times, as far as the temperature is sufficiently high. With this knowledge, a process window can be derived easily in order to produce welds with high strength and short welding times.}, language = {en} } @article{KaesbauerSchmailzlWeberetal., author = {K{\"a}sbauer, Johannes and Schmailzl, Anton and Weber, Ulrich and Hierl, Stefan and Jaus, Tobias and Schwalme, Michael}, title = {Simulationsgest{\"u}tzte Evaluierung von Strahloszillationsmustern beim quasi-simultanen Laser-Durchstrahlschweißen}, series = {JOINING PLASTICS - F{\"u}gen von Kunststoffen}, volume = {13}, journal = {JOINING PLASTICS - F{\"u}gen von Kunststoffen}, number = {2}, publisher = {DVS-Verl., Verl. f{\"u}r Schweißen und Verwandte Verfahren}, address = {D{\"u}sseldorf}, pages = {102 -- 109}, language = {de} } @inproceedings{QuandtSchroeckerHierl, author = {Quandt, Benjamin and Schr{\"o}cker, Korbinian and Hierl, Stefan}, title = {Prozess{\"u}berwachung beim quasi-simultanen Laser-Durchstrahlschweißen glasfaserverst{\"a}rkter Thermoplaste}, series = {9. Landshuter Leichtbau-Colloquium: Leichtbau in Forschung und industrieller Anwendung von der Nano- bis zur Makroebene, 27. / 28. Februar 2019 Hochschule Landshut, Tagungsband zum Colloquium}, booktitle = {9. Landshuter Leichtbau-Colloquium: Leichtbau in Forschung und industrieller Anwendung von der Nano- bis zur Makroebene, 27. / 28. Februar 2019 Hochschule Landshut, Tagungsband zum Colloquium}, editor = {Huber, Otto and Bicker, Marc and Patzelt, Peter}, publisher = {LC-Verlag}, address = {Landshut}, pages = {56 -- 64}, language = {de} } @misc{KaesbauerSchmailzlLooseetal., author = {K{\"a}sbauer, Johannes and Schmailzl, Anton and Loose, Tobias and Hierl, Stefan}, title = {Thermo-Mechanical Modeling of Quasi-Simultaneous Laser Transmission Welding using LS-DYNA with Focus on Accuracy of Heat Input Calculation}, series = {Technology Day 2020 - Plastics on the test rig, Traboch, 04.03.2020}, journal = {Technology Day 2020 - Plastics on the test rig, Traboch, 04.03.2020}, language = {en} } @article{HuentelmannHierl, author = {H{\"u}ntelmann, Sven and Hierl, Stefan}, title = {AM-gerechte Bauteilgestaltung}, series = {additive - Das Magazin f{\"u}r generative Fertigung}, journal = {additive - Das Magazin f{\"u}r generative Fertigung}, number = {1}, publisher = {Konradin-Verlag Robert Kohlhammer GmbH}, address = {Leinfelden-Echterdingen}, pages = {57}, language = {de} } @misc{KaesbauerSchmailzlLooseetal., author = {K{\"a}sbauer, Johannes and Schmailzl, Anton and Loose, Tobias and Hierl, Stefan}, title = {Potentials of the EFG-Method for Modeling Quasi-Simultaneous Laser Transmission Welding Considering the Melt Flow}, series = {Simulationsforum 2019 - Schweißen und W{\"a}rmebehandlung, Weimar}, journal = {Simulationsforum 2019 - Schweißen und W{\"a}rmebehandlung, Weimar}, language = {en} } @inproceedings{HuentelmannHierl, author = {H{\"u}ntelmann, Sven and Hierl, Stefan}, title = {Methodisches Vorgehen bei der Topologieoptimierung additiv gefertigter Bauteile}, series = {Technikforum 3D Druck - Innovative Ans{\"a}tze f{\"u}r Bauteiloptimierung, Design und Konstruktion. Technologie Centrum Westbayern, 27.11.2018}, booktitle = {Technikforum 3D Druck - Innovative Ans{\"a}tze f{\"u}r Bauteiloptimierung, Design und Konstruktion. Technologie Centrum Westbayern, 27.11.2018}, language = {de} } @misc{MaiwaldHierl, author = {Maiwald, Frederik and Hierl, Stefan}, title = {Absorberfreies Laser-Durchstrahlschweißen transparenter Kunststoffe}, series = {InnovationForum Medizintechnik, Tuttlingen, 24.10.2019}, journal = {InnovationForum Medizintechnik, Tuttlingen, 24.10.2019}, language = {de} } @techreport{SchillingerGoerlachHierl, author = {Schillinger, Moritz and G{\"o}rlach, Julien and Hierl, Stefan}, title = {Erstellung eines Konstruktionskatalogs f{\"u}r die additive Fertigung}, series = {Forschung 2018}, journal = {Forschung 2018}, editor = {Baier, Wolfgang}, organization = {Ostbayerische Technische Hochschule Regensburg}, pages = {70 -- 71}, abstract = {Die additive Fertigung bietet vielf{\"a}ltige M{\"o}glichkeiten hinsichtlich der Bauteilgestaltung. Jedoch sind auch bei den generativen Fertigungsverfahren konstruktive Randbedingungen zu beachten, um Bauteile kosteng{\"u}nstig und mit optimalen Eigenschaften herzustellen. Es ist bereits umfangreiche Fachliteratur erh{\"a}ltlich, die entsprechende Konstruktionsempfehlungen gibt. Um Produktentwickler bedarfsgerecht zu unterst{\"u}tzen, ist jedoch ein Nachschlagewerk erforderlich, das mit geeigneter Systematik Konstruktionsvorschl{\"a}ge ausgibt, die zur aktuellen Problemstellung passen. Aufbauend auf dem Stand der Technik, eigenen Analysen und experimentellen Untersuchungen werden erste Ans{\"a}tze f{\"u}r ein solches Nachschlagewerk vorgestellt.}, subject = {Rapid prototyping}, language = {de} } @techreport{Hierl, author = {Hierl, Stefan}, title = {Forschungsschwerpunkte im Labor Lasermaterialbearbeitung}, series = {Forschungsbericht 2017}, journal = {Forschungsbericht 2017}, editor = {Baier, Wolfgang}, organization = {Ostbayerische Technische Hochschule Regensburg}, pages = {56 -- 57}, abstract = {Durch das Laserkunststoffschweißen k{\"o}nnen sowohl filigrane N{\"a}hte in der Mikrotechnik als auchtragf{\"a}hige Verbindungen f{\"u}r Strukturbauteile hergestellt werden. In der Automotiv- oder der Medizintechnik-Industrie ist diese F{\"u}getechnologie mittlerweile etabliert, jedoch sind die Anwen-dungsm{\"o}glichkeiten bei Weitem noch nicht ausgesch{\"o}pft. In k{\"u}rzlich gestarteten Forschungsprojekten mit regionalen Industrieunternehmen und internationalen Forschungspartnern werden im Labor Lasermaterialbearbeitung weitere Potenziale gehoben.}, subject = {Laserschweissen}, language = {de} } @inproceedings{SchmailzlStegerHierl, author = {Schmailzl, Anton and Steger, Sebastian and Hierl, Stefan}, title = {Herausforderungen bei der Integration einer pyrometrischen Temperaturmesstechnik in 3D-Laserscansysteme}, series = {Photonikseminar Kalibrierung des 2D- und 3D-Arbeitsfeldes von Laser-Scan-Systemen, 31.Mai 2017}, booktitle = {Photonikseminar Kalibrierung des 2D- und 3D-Arbeitsfeldes von Laser-Scan-Systemen, 31.Mai 2017}, editor = {bayern photonics e.V., and Bayerisches Laserzentrum GmbH,}, address = {N{\"u}rnberg}, pages = {48 -- 56}, language = {de} } @inproceedings{SchmailzlHierl, author = {Schmailzl, Anton and Hierl, Stefan}, title = {Scanner-integrierte Temperaturmesstechnik beim Laser-Durchstrahlschweißen}, series = {Laser in der Elektronikproduktion \& Feinwerktechnik - LEF 2017, Tagungsband des 20. Seminars LEF 2017, 07.-08. M{\"a}rz 2017}, booktitle = {Laser in der Elektronikproduktion \& Feinwerktechnik - LEF 2017, Tagungsband des 20. Seminars LEF 2017, 07.-08. M{\"a}rz 2017}, editor = {Schmidt, Michael and Roth, S.}, address = {F{\"u}rth}, pages = {181 -- 192}, language = {de} } @inproceedings{KaesbauerSchmailzlHierl, author = {K{\"a}sbauer, Johannes and Schmailzl, Anton and Hierl, Stefan}, title = {Simulationsgest{\"u}tzte Prozessentwicklung beim Laser Durchstrahlschweißen von Thermoplasten ohne absorbierende F{\"u}llstoffe}, series = {36. CADFEM ANSYS Simulation Conference, 10.-12. Oktober 2018, Leipzig}, booktitle = {36. CADFEM ANSYS Simulation Conference, 10.-12. Oktober 2018, Leipzig}, pages = {1 -- 9}, language = {de} } @inproceedings{MeisnerForstnerKaftiranisetal., author = {Meisner, Dennis and Forstner, Lukas and Kaftiranis, Nikitas and Hierl, Stefan}, title = {Investigation of process improvements through laser preheating in extrusion-based additive manufacturing process}, series = {Lasers in Manufacturing Conference (LIM 2023), 26. Juni bis 29. Juni 2023, M{\"u}nchen}, booktitle = {Lasers in Manufacturing Conference (LIM 2023), 26. Juni bis 29. Juni 2023, M{\"u}nchen}, publisher = {Wissenschaftliche Gesellschaft Lasertechnik und Photonik e.V. (WLT)}, pages = {10}, abstract = {Fused layer modeling (FLM) is widely used and is gaining more acceptance in the industry mainly due to its material variety and low costs. However, the usage is limited by a process-related anisotropy of the produced parts. The strength and ductility of the printed parts are significantly lower in the build-up direction than perpendicular to it. This is caused by insufficient interlayer bonding resulting from a reduced surface temperature in the process zone. To overcome this problem, a diode laser is integrated into the conventional FLM process to increase the surface temperature between the already printed surface and the newly applied substrate directly at the deposition zone. The investigations carried out show a significant improvement in the mesostructure, as well as a clear reduction in the anisotropy of the printed test specimens.}, language = {en} } @article{MaiwaldRoiderSchmidtetal., author = {Maiwald, Frederik and Roider, Clemens and Schmidt, Michael and Hierl, Stefan}, title = {Optical Coherence Tomography for 3D Weld Seam Localization in Absorber-Free Laser Transmission Welding}, series = {Applied Sciences}, volume = {12}, journal = {Applied Sciences}, number = {5}, publisher = {MPDI}, address = {Basel}, doi = {10.3390/app12052718}, pages = {1 -- 11}, abstract = {Quality and reliability are of the utmost importance for manufacturing in the optical and medical industries. Absorber-free laser transmission welding enables the precise joining of identical polymers without additives or adhesives and is well-suited to meet the demands of the aforementioned industries. To attain sufficient absorption of laser energy without absorbent additives, thulium fiber lasers, which emit in the polymers' intrinsic absorption spectrum, are used. Focusing the laser beam with a high numerical aperture provides significant intensity gradients inside the workpiece and enables selective fusing of the internal joining zone without affecting the surface of the device. Because seam size and position are crucial, the high-quality requirements demand internal weld seam monitoring. In this work, we propose a novel method to determine weld seam location and size using optical coherence tomography. Changes in optical material properties because of melting and re-solidification during welding allow for weld seam differentiation from the injection-molded base material. Automatic processing of the optical coherence tomography data enables the identification and measurement of the weld seam geometry. The results from our technique are consistent with microscopic images of microtome sections and demonstrate that weld seam localization in polyamide 6 is possible with an accuracy better than a tenth of a millimeter.}, language = {en} } @article{MaiwaldKrothGeigeretal., author = {Maiwald, Frederik and Kroth, Lea and Geiger, Ren{\´e} and Schmitt, Bernhard and Hierl, Stefan and Schmidt, Michael}, title = {Laser welding of polymer foils with spatially adapted intensity distributions}, series = {Joining Plastics}, journal = {Joining Plastics}, number = {1}, publisher = {DVS Media}, address = {D{\"u}sseldorf}, issn = {1864-3450}, doi = {10.53192/JP20250146}, pages = {46 -- 52}, abstract = {Absorber-free laser transmission welding is characterized by its contactless energy input and geometricflexibility and enables the precise and clean joining of polymer films without absorbing additives or adhesives. It is therefore well suited for applications with high demands regarding process reliability and cleanliness such as packaging, fluid containersor as sealing film in medicaland food industry. A homogeneous weld seam temperature is necessary for a large processwindow. In this work, the naturally Gaussian-shaped intensity distributionof the laser beam is there foreconverted into a donut-shaped and a flat-top-shaped distribution. When using the donut-shape, the processwindow for welding polypropylene or polyethylene films is increased by up to a factor of 3. At the same time, the weld seam strength almost corresponds to the strength of the base material.}, subject = {Laserschweissen}, language = {en} } @misc{MaiwaldDzaficHierl, author = {Maiwald, Frederik and Dzafic, Adelisa and Hierl, Stefan}, title = {Messung der Schmelzefließgeschwindigkeit beim Laser-Durchstrahlschweißen von Kunststoffen}, series = {Laser in der Elektronikproduktion \& Feinwerktechnik - LEF 2021, Erlangen, 22.04.2021}, journal = {Laser in der Elektronikproduktion \& Feinwerktechnik - LEF 2021, Erlangen, 22.04.2021}, subject = {Laserdurchstrahlschweissen}, language = {de} } @article{DzaficMaiwaldHierl, author = {Dzafic, Adelisa and Maiwald, Frederik and Hierl, Stefan}, title = {Messung der Schmelzefließgeschwindigkeit beim Laser-Durchstrahlschweißen von Kunststoffen}, series = {Werkstoffe in der Fertigung}, volume = {57}, journal = {Werkstoffe in der Fertigung}, number = {3}, publisher = {HW-Verl.}, address = {Mering}, issn = {0939-2629}, pages = {31 -- 33}, subject = {Laserdurchstrahlschweissen}, language = {de} } @article{HofmannHierl, author = {Hofmann, A. and Hierl, Stefan}, title = {Kontrolliertes Laserdurchstrahlschweißen}, series = {Kunststoffe}, volume = {95}, journal = {Kunststoffe}, number = {6}, publisher = {Hanser}, pages = {36 -- 38}, abstract = {Obwohl das Laserdurchstrahlschweißen sehr reproduzierbar arbeitet, k{\"o}nnen Fehler aus den Vorprozessen Compoundieren, Spritzgießen etc. das Schweißergebnis negativ beeinflussen. Dem Anwender steht inzwischen eine breite Palette an Prozess{\"u}berwachungsmethoden zur Verf{\"u}gung, um eine gleich bleibende Produktqualit{\"a}t zu erzielen.}, language = {de} } @article{MaiwaldHierl, author = {Maiwald, Frederik and Hierl, Stefan}, title = {Absorber-free laser transmission welding of transparent polymers}, series = {Laser Systems Europe}, volume = {50}, journal = {Laser Systems Europe}, number = {Spring 2021}, publisher = {Europa Science}, address = {Cambridge}, language = {en} } @misc{MaiwaldSchulzeSchmidtetal., author = {Maiwald, Frederik and Schulze, Julian and Schmidt, Michael and Hierl, Stefan}, title = {In-situ optical coherence tomography for spatio-temporal analysis of melt pool crystallization in absorber-free laser transmission welding of polymers}, series = {The 9th International Congress on Laser Advanced Materials Processing (LAMP2025), Ise-city, Mie-prefecture, Japan, June 10 to June 13, 2025}, journal = {The 9th International Congress on Laser Advanced Materials Processing (LAMP2025), Ise-city, Mie-prefecture, Japan, June 10 to June 13, 2025}, publisher = {Japan Laser Processing Society}, language = {en} } @article{ReindlMeisnerHierl, author = {Reindl, Thomas and Meisner, Dennis and Hierl, Stefan}, title = {Benchmarking of plastic-based Additive Manufacturing Processes}, series = {RTejournal - Forum f{\"u}r Rapid Technologie}, journal = {RTejournal - Forum f{\"u}r Rapid Technologie}, publisher = {Fachhochschule Aachen}, doi = {https://doi.org/10.58134/fh-aachen-rte_2023_002}, abstract = {Additive Manufacturing (AM) is a future-oriented manufacturing technology that is experiencing an enormous boom in the times of Industry 4.0. As a result, various AM technologies and printer models from different manufacturers are entering the market over a short time span. With the advancing establishment of this manufacturing technology for series applications, the expectations and requirements of the fabricated components are also increasing. However, a major challenge is the application-specific selection of the most suitable AM process due to a lack of comparable data. Furthermore, there needs to be more know-how regarding the geometrical and mechanical characteristics of AM parts. This paper addresses this problem by comparing the three most common plasticbased AM processes in the areas of surface quality, dimensional accuracy, and mechanical properties. Roughness measurements, evaluation of a benchmark artifact, tensile tests, and load increase tests are carried out. Based on the results, the individual possibilities and limitations of the compared AM processes can be detected.}, language = {en} } @inproceedings{MaiwaldKrothLaskinetal., author = {Maiwald, Frederik and Kroth, Lea and Laskin, Alexander and Hierl, Stefan and Schmidt, Michael}, title = {Enlarging the process window in absorber-free laser transmission welding of polymer foils using tailored laser intensity distribution}, series = {Procedia CIRP}, volume = {124}, booktitle = {Procedia CIRP}, publisher = {Elsevier}, doi = {10.1016/j.procir.2024.08.159}, pages = {489 -- 493}, abstract = {Absorber-free laser transmission welding enables precise and clean joining of polymer foils without absorbent additives or adhesives. It is well suited for applications in medical technology and food industry, which impose high demands on process reliability. To achieve a large process window and thus a reliable process, a homogeneous weld seam temperature is desirable. For this purpose, the intensity distribution of the laser beam is adapted locally by refractive beam shaping optics. Using a donut-shaped intensity distribution, the weld seam temperature is homogenized. Thus, the process window for welding polypropylene or polyethylene foils is enlarged up to a factor of 4 compared to a conventional, Gaussian-shaped distribution. This enables the reliable welding of even 85 µm thin foils, which could only be welded to a limited extent with a conventional laser intensity distribution.}, language = {en} } @misc{MaiwaldHierl, author = {Maiwald, Frederik and Hierl, Stefan}, title = {Laser welding device for clamping and welding components and method for clamping and welding components}, organization = {Ostbayerische Technische Hochschule Regensburg}, language = {en} } @inproceedings{MaiwaldFriesSchulzeetal., author = {Maiwald, Frederik and Fries, Fabian and Schulze, Julian and Honnerov{\´a}, Petra and Hierl, Stefan and Schmidt, Michael}, title = {Optical coherence tomography for in situ weld seam monitoring in absorber-free laser transmission welding}, series = {Laser Applications in Microelectronic and Optoelectronic Manufacturing (LAMOM) XXX, 25-31 January 2025, San Francisco, California, United States}, booktitle = {Laser Applications in Microelectronic and Optoelectronic Manufacturing (LAMOM) XXX, 25-31 January 2025, San Francisco, California, United States}, publisher = {SPIE}, doi = {10.1117/12.3040607}, abstract = {Optical and medical devices are frequently made of polymers and place high demands on precision, cleanliness, and reliability of the manufacturing processes used. Absorber-free laser transmission welding is well-suited for joining these devices: the energy input is contactless, no adhesives, additives, or absorbers are required, and the fiber lasers used enable precise weld seams. As the weld seam geometry is decisive for the joint strength and thus crucial for the quality of the product, the welding process is monitored in-situ using Optical Coherence Tomography (OCT). Subsequently, the weld seam geometry is identified automatically using the AI model "Segment Anything" (SAM), which performs semantic segmentation of the OCT data without requiring any training from the user. Welding tests using polyamide six indicate that the seam size is measured with an accuracy of a few hundredths of a millimeter, showing excellent agreement with microscopic images of microtome sections.}, language = {en} } @misc{BeimlerLeisslEbneretal., author = {Beimler, Josef and Leißl, Caroline and Ebner, Lena and Elsner, Michael and M{\"u}hlbauer, Gerhard and Kohlert, Dieter and Schubert, Martin J. W. and Weiß, Andreas P. and Sterner, Michael and Raith, Thomas and Afranseder, Martin and Krapf, Tobias and Mottok, J{\"u}rgen and Siemers, Christian and Großmann, Benjamin and H{\"o}cherl, Johannes and Schlegl, Thomas and Schneider, Ralph and Milaev, Johannes and Rampelt, Christina and Roduner, Christian and Glowa, Christoph and Bachl, Christoph and Schliekmann, Claus and Gnan, Alfons and Grill, Martin and Ruhland, Karl and Piehler, Thomas and Friers, Daniel and Wels, Harald and Pflug, Kenny and Kucera, Markus and Waas, Thomas and Schlachetzki, Felix and Boy, Sandra and Pemmerl, Josef and Leis, Alexander and Welsch, Andreas F.X. and Graf, Franz and Zenger, Gerhard and Volbert, Klaus and Waas, Thomas and Scherzinger, Stefanie and Klettke, Meike and St{\"o}rl, Uta and Heyl, C. and Boldenko, A. and Monkman, Gareth J. and Kujat, Richard and Briem, Ulrich and Hierl, Stefan and Talbot, Sebastian and Schmailzl, Anton and Ławrowski, Robert Damian and Prommesberger, Christian and Langer, Christoph and Dams, Florian and Schreiner, Rupert and Valentino, Piergiorgio and Romano, Marco and Ehrlich, Ingo and Furgiuele, Franco and Gebbeken, Norbert and Eisenried, Michael and Jungbauer, Bastian and Hutterer, Albert and Bauhuber, Michael and Mikrievskij, Andreas and Argauer, Monika and Hummel, Helmut and Lechner, Alfred and Liebetruth, Thomas and Schumm, Michael and Joseph, Saskia and Reschke, Michael and Soska, Alexander and Schroll-Decker, Irmgard and Putzer, Michael and Rasmussen, John and Dendorfer, Sebastian and Weber, Tim and Al-Munajjed, Amir Andreas and Verkerke, Gijsbertus Jacob and Renkawitz, Tobias and Haug, Sonja and Rudolph, Clarissa and Zeitler, Annika and Schaubeck, Simon and Steffens, Oliver and Rechenauer, Christian and Schulz-Brize, Thekla and Fleischmann, Florian and Kusterle, Wolfgang and Beer, Anne and Wagner, Bernd and Neidhart, Thomas}, title = {Forschungsbericht 2013}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, doi = {10.35096/othr/pub-799}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-7990}, pages = {80}, language = {de} } @misc{AppelhansKampmannMottoketal., author = {Appelhans, Marie-Luise and Kampmann, Matthias and Mottok, J{\"u}rgen and Riederer, Michael and Nagl, Klaus and Steffens, Oliver and D{\"u}nnweber, Jan and Wildgruber, Markus and Roth, Julius and Stadler, Timo and Palm, Christoph and Weiß, Martin Georg and Rochholz, Sandra and Bierl, Rudolf and Gschossmann, Andreas and Haug, Sonja and Schmidbauer, Simon and Koch, Anna and Westner, Markus and Bary, Benedikt von and Ellermeier, Andreas and V{\"o}gele, Daniel and Maiwald, Frederik and Hierl, Stefan and Schlamp, Matthias and Ehrlich, Ingo and Siegl, Marco and H{\"u}ntelmann, Sven and Wildfeuer, Matthias and Br{\"u}ckl, Oliver and Sterner, Michael and Hofrichter, Andreas and Eckert, Fabian and Bauer, Franz and Dawoud, Belal and Rabl, Hans-Peter and Gamisch, Bernd and Schmidt, Ottfried and Heberl, Michael and Thema, Martin and Mayer, Ulrike and Eller, Johannes and Sippenauer, Thomas and Adelt, Christian and Haslbeck, Matthias and Vogl, Bettina and Mauerer, Wolfgang and Ramsauer, Ralf and Lohmann, Daniel and Sax, Irmengard and Gabor, Thomas and Feld, Sebastian and Linnhoff-Popien, Claudia and Ławrowski, Robert Damian and Langer, Christoph and Schreiner, Rupert and Sellmair, Josef}, title = {Forschung 2019}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, isbn = {978-3-9818209-7-3}, doi = {10.35096/othr/pub-789}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-7890}, pages = {72}, abstract = {Bericht mit Forschungsprojekten aus verschiedenen Bereichen der OTH Regensburg mit dem Schwerpunktthema "K{\"u}nstliche Intelligenz" und einem Gespr{\"a}ch zur "Medizin der Zukunft"}, subject = {Forschung}, language = {de} } @techreport{BergmeierBockFischeretal., author = {Bergmeier, Sonja and Bock, Maximilian and Fischer, Lukas and Flassig, Nathanael and Hidv{\´e}gi, Barnab{\´a}s and B{\"a}cher, Tim and Hierl, Jonas and Kaltenbach, Dominik and Lackermeier, Florian and Laubmann, Julia and Liebl, Jonas and Pirthauer, Tobias and Reif, Robin and Roider, Stefan}, title = {FMS-Berichte Wintersemester 2024/25}, series = {FMS-Berichte Wintersemester 2024/25}, volume = {2024}, journal = {FMS-Berichte Wintersemester 2024/25}, number = {9}, editor = {Fuhrmann, Thomas and Hipp, Susanne and Niemetz, Michael and Sterz, Oliver}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg / Fakult{\"a}t Elektro- und Informationstechnik}, doi = {10.35096/othr/pub-8312}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-83121}, pages = {76}, abstract = {Dieser Bericht entstand urspr{\"u}nglich auf Initiative der Studierenden des damals neuen Masterstudiengangs „Elektro- und Informationstechnik (MEI)" an der OTH Regensburg, die an der Pflichtlehrveranstaltung „Forschungsmethoden und Seminar (FMS)" im Wintersemester 2020/21 teilnahmen. Diese Lehrveranstaltung hat das Ziel, systematisch an das wissenschaftliche Arbeiten, speziell die Wissenschaftskommunikation, heranzuf{\"u}hren. Daher ist im Laufe der Veranstaltung geeignete Literatur zu einem individuellen Thema zu recherchieren, sind Ver{\"o}ffentlichungen auf ihre Relevanz hin zu beurteilen und letztendlich gilt es eine eigene Ausarbeitung basierend auf der Literaturrecherche zu erstellen und diese in einem Vortrag zu pr{\"a}sentieren. Parallel dazu wird im Theorieteil die entsprechende Hinf{\"u}hrung zu den verschiedenen Elementen der Wissenschaftskommunikation vermittelt: • Bedeutung der Wissenschaftskommunikation f{\"u}r die Arbeit der Ingenieure in Forschung und Entwicklung • Literaturrecherche, Suchmaschinen, Sichtung und Analyse vorhandener Publikationen, Bewertung der Qualit{\"a}t aufgefundener Fachliteratur, Auswahl geeigneter Materialien f{\"u}r die eigene Arbeit • Aufbereitung und Darstellung der recherchierten technischer Inhalte in Form einer seitenanzahlbegrenzten wissenschaftlichen Ausarbeitung • Einhalten formaler Randbedingungen bzgl. Strukturierung, einschl. Bildnachweise und Zitationsstile • Peer-review-Prozess bei wertsch{\"a}tzender Beurteilung der Leistung anderer • Publikumsangepasstes Aufbereiten komplexer fachlicher Inhalte mit hochschul{\"o}ffentlicher Pr{\"a}sentation der Ergebnisse • F{\"u}hren m{\"u}ndlicher wissenschaftlicher Diskurse Die pr{\"a}sentierten Themen beruhen nicht auf eigener Forschungst{\"a}tigkeit, sondern sind als einf{\"u}hrende Reviewartikel zum jeweiligen vorgegebenen technischen oder gesellschaftspolitischen Forschungsthema zu verstehen.}, subject = {Elektrotechnik}, language = {mul} } @misc{BroserFalterŁawrowskietal., author = {Broser, Christian and Falter, Thomas and Ławrowski, Robert Damian and Altenbuchner, Amelie and V{\"o}gele, Daniel and Koss, Claus and Schlamp, Matthias and Dunnweber, Jan and Steffens, Oliver and Heckner, Markus and Jaritz, Sabine and Schiegl, Thomas and Corsten, Sabine and Lauer, Norina and Guertler, Katherine and Koenig, Eric and Haug, Sonja and Huber, Dominik and Birkenmaier, Clemens and Krenkel, Lars and Wagner, Thomas and Justus, Xenia and Saßmannshausen, Sean Patrick and Kleine, Nadine and Weber, Karsten and Braun, Carina N. and Giacoppo, Giuliano and Heinrich, Michael and Just, Tobias and Schreck, Thomas and Schnabl, Andreas and Gilmore, Amador T{\´e}ran and Roeslin, Samuel and Schmid, Sandra and Wellnitz, Felix and Malz, Sebastian and Maurial, Andreas and Hauser, Florian and Mottok, J{\"u}rgen and Klettke, Meike and Scherzinger, Stefanie and St{\"o}rl, Uta and Heckner, Markus and Bazo, Alexander and Wolff, Christian and Kopper, Andreas and Westner, Markus and Pongratz, Christian and Ehrlich, Ingo and Briem, Ulrich and Hederer, Sebastian and Wagner, Marcus and Schillinger, Moritz and G{\"o}rlach, Julien and Hierl, Stefan and Siegl, Marco and Langer, Christoph and Hausladen, Matthias and Schreiner, Rupert and Haslbeck, Matthias and Kreuzer, Reinhard and Br{\"u}ckl, Oliver and Dawoud, Belal and Rabl, Hans-Peter and Gamisch, Bernd and Schmidt, Ottfried and Heberl, Michael and G{\"a}nsbauer, Bianca and Bick, Werner and Ellermeier, Andreas and Monkman, Gareth J. and Prem, Nina and Sindersberger, Dirk and Tschurtschenthaler, Karl and Aurbach, Maximilian and Dendorfer, Sebastian and Betz, Michael A. and Szecsey, Tamara and Mauerer, Wolfgang and Murr, Florian}, title = {Forschung 2018}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, isbn = {978-3-9818209-5-9}, doi = {10.35096/othr/pub-1382}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-13826}, pages = {98}, subject = {Forschung}, language = {de} }