---
_id: '64916'
abstract:
- lang: eng
text: 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.
article_type: original
author:
- first_name: Mohamad
full_name: Al Trjman, Mohamad
id: '65415'
last_name: Al Trjman
- first_name: Felix
full_name: Beule, Felix
id: '66192'
last_name: Beule
- first_name: Dominik
full_name: Teutenberg, Dominik
id: '537'
last_name: Teutenberg
- first_name: Gerson
full_name: Meschut, Gerson
id: '32056'
last_name: Meschut
orcid: 0000-0002-2763-1246
- first_name: Julia
full_name: Riese, Julia
id: '101499'
last_name: Riese
orcid: 0000-0002-3053-0534
citation:
ama: Al Trjman M, Beule F, Teutenberg D, Meschut G, Riese J. Experimental characterization
and numerical analysis of the influence of the CED coating process on viscous
fingering formation in hybrid-jointed mixed structures. The Journal of Adhesion.
Published online 2026:1-24. doi:10.1080/00218464.2026.2644394
apa: Al Trjman, M., Beule, F., Teutenberg, D., Meschut, G., & Riese, J. (2026).
Experimental characterization and numerical analysis of the influence of the CED
coating process on viscous fingering formation in hybrid-jointed mixed structures.
The Journal of Adhesion, 1–24. https://doi.org/10.1080/00218464.2026.2644394
bibtex: '@article{Al Trjman_Beule_Teutenberg_Meschut_Riese_2026, 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},
journal={The Journal of Adhesion}, publisher={Informa UK Limited}, author={Al
Trjman, Mohamad and Beule, Felix and Teutenberg, Dominik and Meschut, Gerson and
Riese, Julia}, year={2026}, pages={1–24} }'
chicago: Al Trjman, Mohamad, Felix Beule, Dominik Teutenberg, Gerson Meschut, and
Julia Riese. “Experimental Characterization and Numerical Analysis of the Influence
of the CED Coating Process on Viscous Fingering Formation in Hybrid-Jointed Mixed
Structures.” The Journal of Adhesion, 2026, 1–24. https://doi.org/10.1080/00218464.2026.2644394.
ieee: 'M. Al Trjman, F. Beule, D. Teutenberg, G. Meschut, and J. Riese, “Experimental
characterization and numerical analysis of the influence of the CED coating process
on viscous fingering formation in hybrid-jointed mixed structures,” The Journal
of Adhesion, pp. 1–24, 2026, doi: 10.1080/00218464.2026.2644394.'
mla: Al Trjman, Mohamad, et al. “Experimental Characterization and Numerical Analysis
of the Influence of the CED Coating Process on Viscous Fingering Formation in
Hybrid-Jointed Mixed Structures.” The Journal of Adhesion, Informa UK Limited,
2026, pp. 1–24, doi:10.1080/00218464.2026.2644394.
short: M. Al Trjman, F. Beule, D. Teutenberg, G. Meschut, J. Riese, The Journal
of Adhesion (2026) 1–24.
date_created: 2026-03-14T18:43:41Z
date_updated: 2026-03-14T19:04:46Z
ddc:
- '620'
- '670'
- '660'
department:
- _id: '9'
doi: 10.1080/00218464.2026.2644394
file:
- access_level: closed
content_type: application/pdf
creator: mohamada
date_created: 2026-03-14T18:50:31Z
date_updated: 2026-03-14T18:50:31Z
file_id: '64917'
file_name: Experimental characterization and numerical analysis of the influence
of the CED coating process on viscous fingering formation in hybrid-jointed mixe.pdf
file_size: 14668789
relation: main_file
success: 1
file_date_updated: 2026-03-14T18:50:31Z
has_accepted_license: '1'
keyword:
- 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).
language:
- iso: eng
main_file_link:
- open_access: '1'
oa: '1'
page: 1-24
publication: The Journal of Adhesion
publication_identifier:
issn:
- 0021-8464
- 1545-5823
publication_status: published
publisher: Informa UK Limited
status: public
title: Experimental characterization and numerical analysis of the influence of the
CED coating process on viscous fingering formation in hybrid-jointed mixed structures
type: journal_article
user_id: '65415'
year: '2026'
...
---
_id: '19973'
abstract:
- lang: eng
text: As a result of lightweight design, increased use is being made of high-strength
steel and aluminium in car bodies. Self-piercing riveting is an established technique
for joining these materials. The dissimilar properties of the two materials have
led to a number of different rivet geometries in the past. Each rivet geometry
fulfils the requirements of the materials within a limited range. In the present
investigation, an improved rivet geometry is developed, which permits the reliable
joining of two material combinations that could only be joined by two different
rivet geometries up until now. Material combination 1 consists of high-strength
steel on both sides, while material combination 2 comprises aluminium on the punch
side and high-strength steel on the die side. The material flow and the stress
and strain conditions prevailing during the joining process are analysed by means
of numerical simulation. The rivet geometry is then improved step-by-step on the
basis of this analysis. Finally, the improved rivet geometry is manufactured and
the findings of the investigation are verified in experimental joining tests.
article_type: original
author:
- first_name: Benedikt
full_name: Uhe, Benedikt
id: '38131'
last_name: Uhe
- first_name: Clara-Maria
full_name: Kuball, Clara-Maria
last_name: Kuball
- first_name: Marion
full_name: Merklein, Marion
last_name: Merklein
- first_name: Gerson
full_name: Meschut, Gerson
id: '32056'
last_name: Meschut
orcid: 0000-0002-2763-1246
citation:
ama: Uhe B, Kuball C-M, Merklein M, Meschut G. Improvement of a rivet geometry for
the self-piercing riveting of high-strength steel and multi-material joints. Production
Engineering. 2020;14:417-423. doi:10.1007/s11740-020-00973-w
apa: Uhe, B., Kuball, C.-M., Merklein, M., & Meschut, G. (2020). Improvement
of a rivet geometry for the self-piercing riveting of high-strength steel and
multi-material joints. Production Engineering, 14, 417–423. https://doi.org/10.1007/s11740-020-00973-w
bibtex: '@article{Uhe_Kuball_Merklein_Meschut_2020, title={Improvement of a rivet
geometry for the self-piercing riveting of high-strength steel and multi-material
joints}, volume={14}, DOI={10.1007/s11740-020-00973-w},
journal={Production Engineering}, author={Uhe, Benedikt and Kuball, Clara-Maria
and Merklein, Marion and Meschut, Gerson}, year={2020}, pages={417–423} }'
chicago: 'Uhe, Benedikt, Clara-Maria Kuball, Marion Merklein, and Gerson Meschut.
“Improvement of a Rivet Geometry for the Self-Piercing Riveting of High-Strength
Steel and Multi-Material Joints.” Production Engineering 14 (2020): 417–23.
https://doi.org/10.1007/s11740-020-00973-w.'
ieee: 'B. Uhe, C.-M. Kuball, M. Merklein, and G. Meschut, “Improvement of a rivet
geometry for the self-piercing riveting of high-strength steel and multi-material
joints,” Production Engineering, vol. 14, pp. 417–423, 2020, doi: 10.1007/s11740-020-00973-w.'
mla: Uhe, Benedikt, et al. “Improvement of a Rivet Geometry for the Self-Piercing
Riveting of High-Strength Steel and Multi-Material Joints.” Production Engineering,
vol. 14, 2020, pp. 417–23, doi:10.1007/s11740-020-00973-w.
short: B. Uhe, C.-M. Kuball, M. Merklein, G. Meschut, Production Engineering 14
(2020) 417–423.
date_created: 2020-10-12T08:14:13Z
date_updated: 2026-02-27T10:41:55Z
department:
- _id: '157'
doi: 10.1007/s11740-020-00973-w
intvolume: ' 14'
keyword:
- Self-piercing riveting
- Joining technology
- Rivet geometry
- Multi-material design
- High-strength steel
- Aluminium
language:
- iso: eng
page: 417-423
publication: Production Engineering
publication_status: published
quality_controlled: '1'
status: public
title: Improvement of a rivet geometry for the self-piercing riveting of high-strength
steel and multi-material joints
type: journal_article
user_id: '53912'
volume: 14
year: '2020'
...