@article{62767, abstract = {{Abstract In this study, we develop a novel multi-fidelity deep learning approach that transforms low-fidelity solution maps into high-fidelity ones by incorporating parametric space information into an autoencoder architecture. This method’s integration of parametric space information significantly reduces the amount of training data needed to effectively predict high-fidelity solutions from low-fidelity ones. In this study, we examine a two-dimensional steady-state heat transfer analysis within a heterogeneous materials microstructure. The heat conductivity coefficients for two different materials are condensed from a 101  $$\times $$ ×  101 grid to smaller grids. We then solve the boundary value problem on the coarsest grid using a pre-trained physics-informed neural operator network known as Finite Operator Learning (FOL). The resulting low-fidelity solution is subsequently upscaled back to a 101  $$\times $$ ×  101 grid using a newly designed enhanced autoencoder. The novelty of the developed enhanced autoencoder lies in the concatenation of heat conductivity maps of different resolutions to the decoder segment in distinct steps. Hence the developed algorithm is named microstructure-embedded autoencoder (MEA). We compare the MEA outcomes with those from finite element methods, the standard U-Net, and an interpolation approach as an upscaling technique. Our analysis shows that MEA outperforms these methods in terms of computational efficiency and error on representative test cases. As a result, the MEA serves as a potential supplement to neural operator networks, effectively upscaling low-fidelity solutions to high-fidelity while preserving critical details often lost in traditional upscaling methods, such as sharp interfaces features lost in the context of interpolation approaches.}}, author = {{Najafi Koopas, Rasoul and Rezaei, Shahed and Rauter, Natalie and Ostwald, Richard and Lammering, Rolf}}, issn = {{0178-7675}}, journal = {{Computational Mechanics}}, number = {{4}}, pages = {{1377--1406}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Introducing a microstructure-embedded autoencoder approach for reconstructing high-resolution solution field data from a reduced parametric space}}}, doi = {{10.1007/s00466-024-02568-z}}, volume = {{75}}, year = {{2024}}, } @article{62770, abstract = {{AbstractThe open-source parameter identification tool ADAPT (A diversely applicable parameter identification Tool) is integrated with a machine learning-based approach for start value prediction in order to calibrate a Gurson–Tvergaard–Needleman (GTN) and a Lemaitre damage model. As representative example case-hardened steel 16MnCrS5 is elaborated. An artificial neural network (ANN) is initially trained by using load–displacement curves derived from simulations of a boundary value problem—instead of using data generated for homogeneous states of deformation at material point or one-element level—with varying material parameter combinations. The ANN is then employed so as to predict sets of material parameters that already provide close solutions to the experiment. These predicted parameter sets serve as starting values for a subsequent multi-objective parameter identification by using ADAPT. ADAPT allows for the consideration of input data from multiple scales, including integral data such as load–displacement curves, full-field data such as displacement and strain fields, and high-resolution experimental void data at the micro-scale. The influence of each data set on prediction quality is analyzed. Using various types of input data introduces additional information, enhancing prediction accuracy. The validation is carried out with respect to experimental void measurements of forward rod extruded parts. The results demonstrate, by incorporating void measurements in the optimization process, that it is possible to improve the quantitative prediction of ductile damage in the sense of void area fractions by factor 28 in forward rod extrusion.}}, author = {{Gerlach, Jan and Schulte, Robin and Schowtjak, Alexander and Clausmeyer, Till and Ostwald, Richard and Tekkaya, A. Erman and Menzel, Andreas}}, issn = {{0939-1533}}, journal = {{Archive of Applied Mechanics}}, number = {{8}}, pages = {{2217--2242}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Enhancing damage prediction in bulk metal forming through machine learning-assisted parameter identification}}}, doi = {{10.1007/s00419-024-02634-1}}, volume = {{94}}, year = {{2024}}, } @article{62768, author = {{Najafi Koopas, Rasoul and Rezaei, Shahed and Rauter, Natalie and Ostwald, Richard and Lammering, Rolf}}, issn = {{0013-7944}}, journal = {{Engineering Fracture Mechanics}}, publisher = {{Elsevier BV}}, title = {{{A spatiotemporal deep learning framework for prediction of crack dynamics in heterogeneous solids: Efficient mapping of concrete microstructures to its fracture properties}}}, doi = {{10.1016/j.engfracmech.2024.110675}}, volume = {{314}}, year = {{2024}}, } @unpublished{56289, author = {{Seeger, Karl and Genovese, Matteo and Schlüter, Alexander and Kockel, Christina and Corigliano, Orlando and Díaz Canales, Edith Benjamina and Fragiacomo, Petronilla and Praktiknjo, Aaron}}, booktitle = {{United States Association for Energy Economics (USAEE) & International Association for Energy Economics (IAEE) Research Paper Series}}, publisher = {{Elsevier BV}}, title = {{{Evaluating Supply Scenarios for Hydrogen and Green Fuels from Canada, Chile, and Algeria to Germany via a Techno-Economic Assessment}}}, year = {{2024}}, } @inproceedings{56357, author = {{Díaz Canales, Edith Benjamina and Avila , Alfredo and Schlüter, Sabine and Lacayo, Erick and Schlüter, Alexander}}, booktitle = {{19th Conference on Sustainable Development of Energy, Water and Environment Systems}}, location = {{Rome}}, publisher = {{ Faculty of Mechanical Engineering and Naval Architecture, Zagreb}}, title = {{{Implementing Strategic Environmental Assessment (SEA) in the Global South, a challenge: Nicaragua as a case study.}}}, year = {{2024}}, } @article{57540, abstract = {{AbstractRolling processes of conventional cast Al-Li alloys quickly reach their limits due to relatively poor material formability. This can be overcome by using twin-roll casting to produce thin sheets. Further thermomechanical treatment, including hot or cold rolling, and heat treatment can adjust the mechanical properties of twin-roll cast Al-Li sheets. The whole manufacturing chain requires detailed knowledge of the precipitation and dissolution behavior during heating, soaking and cooling, to purposefully select any process parameters. This study shows the process chain of a twin-roll cast Al–Cu–Li alloy achieving a hardness of around 180 HV1 by adapting the heat treatment parameters for homogenisation, hot rolling and age hardening. Both hardness and microstructure evolution are visualised along the process chain.}}, author = {{Mallow, Sina and Broer, Jette and Milkereit, Benjamin and Grydin, Olexandr and Hoyer, Kay-Peter and Garthe, Kai-Uwe and Milaege, Dennis and Boyko, Viktoriya and Schaper, Mirko and Kessler, Olaf}}, issn = {{0944-6524}}, journal = {{Production Engineering}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Process chain of a twin-roll cast aluminium-copper-lithium alloy}}}, doi = {{10.1007/s11740-024-01322-x}}, year = {{2024}}, } @article{58309, abstract = {{This study evaluates four widely used fracture simulation methods, comparing their computational expenses and implementation complexities within the finite element (FE) framework when employed on heterogeneous solids. Fracture methods considered encompass the intrinsic cohesive zone model (CZM) using zero-thickness cohesive interface elements (CIEs), the standard phase-field fracture (SPFM) approach, the cohesive phase-field fracture (CPFM) approach, and an innovative hybrid model. The hybrid approach combines the CPFM fracture method with the CZM, specifically applying the CZM within the interface zone. The finite element model studied is characterized by three specific phases: inclusions, matrix, and the interface zone. This case study serves as a potential template for meso- or micro-level simulations involving a variety of composite materials. The thorough assessment of these modeling techniques indicates that the CPFM approach stands out as the most effective computational model, provided that the thickness of the interface zone is not significantly smaller than that of the other phases. In materials like concrete, which contain interfaces within their microstructure, the interface thickness is notably small when compared to other phases. This leads to the hybrid model standing as the most authentic finite element model, utilizing CIEs within the interface to simulate interface debonding. A significant finding from this investigation is that within the CPFM method, for a specific interface thickness, convergence with the hybrid model can be observed. This suggests that the CPFM fracture method could serve as a unified fracture approach for multiphase materials when a specific interfacial thickness is used. In addition, this research provides valuable insights that can advance efforts to fine-tune material microstructures. An investigation of the influence of interfacial material properties, voids, and the spatial arrangement of inclusions shows a pronounced effect of these parameters on the fracture toughness of the material.}}, author = {{Najafi Koopas, Rasoul and Rezaei, Shahed and Rauter, Natalie and Ostwald, Richard and Lammering, Rolf}}, issn = {{2076-3417}}, journal = {{Applied Sciences}}, number = {{1}}, publisher = {{MDPI AG}}, title = {{{Comparative Analysis of Phase-Field and Intrinsic Cohesive Zone Models for Fracture Simulations in Multiphase Materials with Interfaces: Investigation of the Influence of the Microstructure on the Fracture Properties}}}, doi = {{10.3390/app15010160}}, volume = {{15}}, year = {{2024}}, } @phdthesis{58981, abstract = {{Die Auslegung von gefügten Bauteilen ermöglicht die Produktion von Strukturbauteilen, welche teils aus sehr vielen Einzelteilen bestehen und durch eine hohe Anzahl von Fügepunkten verbunden sind. Die Eigenschaften der Einzelteile und die Prozessgrößen in der Fertigung unterliegen Schwankungen, die bei der Auslegung berücksichtigt werden müssen. Um diese Bauteile stets nach der Spezifikation zu liefern, werden die Prozesse gewöhnlich über die gesamte Prozesskette überwacht und das Bauteil überdimensioniert. Treten unvorhersehbare Störungen in der Prozesskette auf, kann das Bauteil nicht mehr weiter produziert werden. Entweder muss die Störung im Prozess behoben werden, was nicht immer möglich ist und die schon teils produzierte Charge muss vernichtet werden, oder der Teil der Prozesskette nach der Störung muss angepasst werden. Dies kann z.B. durch eine Änderungskonstruktion, wie der Anpassung der Fügepunktpositionen und der -anzahl, geschehen. In dieser Dissertation wurde eine Auslegungsmethode zur strukturellen elastischen Auslegung punktgefügter Bauteile entwickelt, mit der eine Anpassungskonstruktion, z.B. auf solche Störungen, möglich ist. Diese Methode basiert auf der Ausnutzung des Einflusses von geometrischen Bauteilgrößen, wie z.B. der Bauteildicke und der Fügepunktpositionierung, von veränderten Fügepunkteigenschaften sowie dem Verständnis zwischen Prozessgrößen und den erzeugten Fügepunkteigenschaften.}}, author = {{Martin, Sven}}, pages = {{153}}, publisher = {{LibreCat University}}, title = {{{Holistische Methode zur elastischen Auslegung von geclinchten Bauteilen}}}, doi = {{10.17619/UNIPB/1-2120}}, year = {{2024}}, } @inproceedings{57202, author = {{Ostermann, Moritz and Marten, Thorsten and Tröster, Thomas}}, booktitle = {{16th Biennial International Conference on EcoBalance}}, keywords = {{Life Cycle Sustainability Assessment, Prospective Life Cycle Assessment, Life Cycle Engineering, On-Demand Mobility, Mobility Services}}, location = {{Sendai, Japan}}, title = {{{Prospective Life Cycle Assessment of Lightweight Structures in Vehicles for On-Demand Mobility Systems}}}, year = {{2024}}, } @inproceedings{57537, author = {{Ostermann, Moritz and Marten, Thorsten and Tröster, Thomas}}, booktitle = {{Sustainability in Product and Production Engineering}}, location = {{Bad Nauheim}}, publisher = {{Automotive Circle}}, title = {{{Scenario-based life cycle assessment of vehicle lightweight structures}}}, year = {{2024}}, } @article{58381, author = {{Suresh, Keenatampalle and Kesavulu, C.R. and Chalicheemalapalli Jayasankar, Deviprasad and Pecharapa, Wisanu and Kagola, Upendra Kumar and Tröster, Thomas and Jayasankar, C.K.}}, issn = {{0022-2313}}, journal = {{Journal of Luminescence}}, publisher = {{Elsevier BV}}, title = {{{Stokes and anti-Stokes emission characteristics of Er3+/Yb3+ co-doped zinc tellurite glasses under 377 and 1550 nm excitations for solar energy conversion application}}}, doi = {{10.1016/j.jlumin.2024.120948}}, volume = {{277}}, year = {{2024}}, } @article{58380, author = {{Kesavulu, C.R. and Basavapoornima, Ch. and Ramprasad, Pikkili and Chalicheemalapalli Jayasankar, Deviprasad and Depuru, Shobha Rani and Jayasankar, C.K.}}, issn = {{2667-0224}}, journal = {{Chemical Physics Impact}}, publisher = {{Elsevier BV}}, title = {{{Optical and photoluminescence characteristics of Pr3+-doped P2O5 +BaO+La2O3 glasses}}}, doi = {{10.1016/j.chphi.2024.100797}}, volume = {{10}}, year = {{2024}}, } @inproceedings{59160, author = {{Moritzer, Elmar and Völklein, Paul Leonhard}}, booktitle = {{DVS Sitzung FA11 - Kunststofffügen}}, publisher = {{DVS}}, title = {{{Praxisrelevante Aspekte des Stempelnietens für Organoblech-Metall-Hybridverbindungen}}}, year = {{2024}}, } @inproceedings{59161, author = {{Moritzer, Elmar and Held, Christian}}, booktitle = {{DVS Sitzung FA11 - Kunststofffügen}}, title = {{{Werkstoffgerechte Auslegung von Direktverschraubungen in SMC/BMC Bauteilen}}}, year = {{2024}}, } @inproceedings{59158, author = {{Schöppner, Volker and Arndt, Theresa}}, booktitle = {{DVS Plenarsitzung AG W4 Fügen von Kunststoffen}}, publisher = {{DVS}}, title = {{{Ambossfreies Ultraschallschweißen für nur einseitig zugängliche Schweißsituationen}}}, year = {{2024}}, } @inproceedings{59157, author = {{Schöppner, Volker and Arndt, Theresa}}, booktitle = {{DVS Sitzung FA11 - Kunststofffügen}}, publisher = {{DVS}}, title = {{{Anbossfreies Ultraschallschweißen für nur einseitig zugängliche Schweißsituationen}}}, year = {{2024}}, } @inproceedings{59162, author = {{Schöppner, Volker and Arndt, Theresa}}, booktitle = {{DVS Sitzung FA11 - Kunststofffügen}}, publisher = {{DVS}}, title = {{{Ambossfreies Ultraschallschweißen für nur einseitig zugängliche Schweißsituationen}}}, year = {{2024}}, } @inproceedings{59156, author = {{Moritzer, Elmar and Held, Christian}}, booktitle = {{DVS Sitzung FA11 - Kunststofffügen}}, publisher = {{DVS}}, title = {{{Werkstoffgerechte Auslegung von Direktverschraubungen in SMC/BMC Bauteilen}}}, year = {{2024}}, } @inproceedings{59139, author = {{Moritzer, Elmar and Held, Christian}}, booktitle = {{77th Annual Assembly of the International Institute of Welding}}, title = {{{Influence of the screw dome geometry on the mechanical strength of direct screw fastened SMC/BMC components}}}, year = {{2024}}, } @inproceedings{59136, author = {{Moritzer, Elmar and Rauen, Dennis}}, booktitle = {{VDI-Jahrestagung Spritzgießen}}, title = {{{Inline Plasmavorbehandlung im Mehrkomponentenspritzgießen - InMould-Plasma}}}, year = {{2024}}, }