@article{64916,
  abstract     = {{The joining of dissimilar materials, such as steel and aluminum, entails significant challenges during thermal curing processes due to differing coefficients of thermal expansion. This study addresses the formation of “viscous fingering” instabilities in structural adhesive joints, which are induced by thermally driven relative displacements during the liquid phase of the adhesive. Using a component-like specimen “bridge specimen,” the dependency of this phenomenon on process temperature and structural stiffness (rivet distance) was characterized. Experimental results reveal that while the relative displacement scales cubically with the free buckling length, the resulting adhesive area reduction follows an exponential trend, leading to a loss of effective bond area of up to 79%, which significantly compromises the joint strength in automotive applications. To predict these process-induced defects, a thermo-chemo-viscoelastic-viscoplastic adhesive model implemented in LS-DYNA was applied. The model combines curing kinetics, viscoelastic relaxation, and pressure-dependent plasticity and features a geometric damage parameter (D) that captures the adhesive area reduction caused by viscous fingering as an exponential function of the accumulated normal strain in the liquid phase. This damage parameter, calibrated on base-specimen level, was transferred to the component geometry. The simulation demonstrated high predictive accuracy with a maximum deviation of the adhesive area reduction of 3.1% compared to experimental data. This validates the model’s capability to predict manufacturing-induced damage in complex hybrid structures solely based on thermal boundary conditions.}},
  author       = {{Al Trjman, Mohamad and Beule, Felix and Teutenberg, Dominik and Meschut, Gerson and Riese, Julia}},
  issn         = {{0021-8464}},
  journal      = {{The Journal of Adhesion}},
  keywords     = {{Adhesive area reduction, CED coating process, delta alpha problem, epoxy structural adhesive, influence of manufacture, multi-material design, numerical simulation (FEM), relative displacements, viscous fingering (saffman-taylor-instability).}},
  pages        = {{1--24}},
  publisher    = {{Informa UK Limited}},
  title        = {{{Experimental characterization and numerical analysis of the influence of the CED coating process on viscous fingering formation in hybrid-jointed mixed structures}}},
  doi          = {{10.1080/00218464.2026.2644394}},
  year         = {{2026}},
}

@article{58672,
  author       = {{Al Trjman, Mohamad and Salten, Alexander Heinrich Johannes and Beule, Felix and Teutenberg, Dominik and Meschut, Gerson and Riese, Julia and Kenig, Eugeny}},
  issn         = {{0143-7496}},
  journal      = {{International Journal of Adhesion and Adhesives}},
  publisher    = {{Elsevier BV}},
  title        = {{{Viscous fingering in adhesive bonding}}},
  doi          = {{10.1016/j.ijadhadh.2025.103960}},
  volume       = {{139}},
  year         = {{2025}},
}

@inproceedings{52403,
  author       = {{Al Trjman, Mohamad and Meschut, Gerson and Salten, Alexander Heinrich Johannes and Kenig, Eugeny Y.}},
  location     = {{Köln}},
  title        = {{{Methodenentwicklung zur Simulation des Viscous Fingering in Klebverbindungen von stahlintensiven Mischbaustrukturen}}},
  year         = {{2024}},
}

@inproceedings{54142,
  author       = {{Beule, Felix and Al Trjman, Mohamad and Teutenberg, Dominik and Meschut, Gerson}},
  location     = {{Shanghai}},
  title        = {{{Method development (modelling, simulation, characterisation) in adhesive bonding technology}}},
  year         = {{2024}},
}

@inproceedings{44228,
  author       = {{Salten, Alexander Heinrich Johannes and Al Trjman, Mohamad and Meschut, Gerson and Kenig, Eugeny Y.}},
  location     = {{Paderborn}},
  title        = {{{Simulation des „viscous fingering“ Effektes in Klebverbindungen}}},
  year         = {{2023}},
}

@inproceedings{44227,
  author       = {{Al Trjman, Mohamad and Meschut, Gerson and Salten, Alexander Heinrich Johannes and Kenig, Eugeny Y.}},
  location     = {{Frankfurt am Main}},
  title        = {{{Methodenentwicklung zur Simulation des Viscous Fingering in Klebverbindungen von stahlintensiven Mischbaustrukturen}}},
  year         = {{2023}},
}

@inproceedings{29856,
  author       = {{Jamei, Said and Döller, Norbert and Lossau, Sebastian and Beule, Felix and Al Trjman, Mohamad and Aubel, Tobias and Meschut, Gerson and Sommer, Daniel and Facciotto, Silvio and Droste, Alexander and Haufe, Andre and Helbig, Martin and Gleich, Henning and Kose, Kim}},
  booktitle    = {{22. Kolloquium: Gemeinsame Forschung in der Klebtechnik}},
  title        = {{{DigiBody - Digitale Prozesskette zur Abbildung und Optimierung der Fügetechnik im Rohbau }}},
  year         = {{2022}},
}

@inproceedings{42239,
  author       = {{Klöppel, Thomas and Haufe, Andre and Helbig, Martin and Liebold, Christian and Beule, Felix and Al Trjman, Mohamad and Aubel, Tobias and Meschut, Gerson and Jamei, Said and Fürle, Fabian and Lossau, Sebastian and Droste, Alexander and Gleich, Henning and Kose, Kim and Sommer, Daniel and Facciotto, Silvio}},
  booktitle    = {{4a-Technologietage 2022}},
  location     = {{Schladming}},
  title        = {{{A new viscoelastic-viscoplastic constitutive formulation in LS-DYNA to model adhesives during the complete manufacturing-crashworthiness process chain}}},
  year         = {{2022}},
}