@article{DostalekStegerSchmailzletal., author = {Dostalek, Michael and Steger, Sebastian and Schmailzl, Anton and Hierl, Stefan}, title = {Detecting Defects Reliably}, series = {Kunststoffe International}, volume = {105}, journal = {Kunststoffe International}, number = {12}, pages = {37 -- 40}, abstract = {The integration of a broadband pyrometer in a 3-D scanner enables a continuous and local temperature measurement during the quasi-simultaneous laser transmission welding process. Welding tests on polyethylene samples show that defects can be clearly identified based on the temperature signal, despite a high scanning velocity.}, language = {en} } @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} } @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} } @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} } @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} } @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} } @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{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} } @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} } @phdthesis{Schmailzl, author = {Schmailzl, Anton}, title = {Festigkeits- und zeitoptimierte Prozessf{\"u}hrung beim quasi-simultanen Laser-Durchstrahlschweißen}, editor = {Franke, J{\"o}rg and Hanenkamp, Nico and Hausotte, Tino and Merklein, Marion and M{\"u}ller, Sebastian and Schmidt, Michael and Wartzack, Sandro}, publisher = {FAU University Press}, address = {Erlangen}, doi = {10.25593/978-3-96147-584-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:29-opus4-207070}, pages = {xiii, 157}, abstract = {Mit Blick auf Leichtbauanwendungen ist der Bedarf an thermoplastischen Strukturbauteilen sowohl in der Automobil- als auch in der Luftfahrtindustrie in den letzten Jahren deutlich angestiegen. Das quasi-simultane Laser-Durchstrahlschweißen ist ein etabliertes Kunststoffschweißverfahren, welches jedoch zur Herstellung von tragenden und sicherheitsrelevanten Bauteilen bislang kaum in Betracht gezogen wird. In der vorliegenden Arbeit wird die Korrelation zwischen dem Prozessablauf und der Schweißnahtfestigkeit beim quasi-simultanen Laser-Durchstrahlschweißen von Polyamid 6 (Ultramid B3s) erstmalig untersucht. Zur Prozessanalyse wird ein 3D-Scanner mit integriertem Pyrometer realisiert und f{\"u}r die Messaufgabe kalibriert. Es wird gezeigt, dass die detektierte W{\"a}rmestrahlung dem Kern der Schweißnaht zuzuordnen ist. Die Kerntemperatur in der quasi-station{\"a}ren Prozessphase steht in direkter Korrelation mit der Schweißnahtfestigkeit. Mit steigender Kerntemperatur bzw. Molek{\"u}lbeweglichkeit erh{\"o}ht sich die Wahrscheinlichkeit der Bildung von Molek{\"u}l-Verschlaufungen in der F{\"u}geebene. Zur Ermittlung der Kerntemperatur ist sowohl die in dieser Arbeit entwickelte Temperaturmesstechnik als auch die realisierte numerische Prozesssimulation nutzbar. Die Erkenntnisse in dieser Arbeit sind f{\"u}r eine festigkeits- und zeitoptimierten Prozessf{\"u}hrung des quasi-simultanen Laser-Durchstrahlschweißens nutzbar.}, language = {de} }