@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} }