---
_id: '58492'
abstract:
- lang: eng
text: A coupled finite plasticity ductile damage and failure model is proposed for
the finite element simulation of clinch joining, which incorporates stress-state
dependency and regularisation by gradient-enhancement of the damage variable.
Ductile damage is determined based on a failure indicator governed by a failure
surface in stress space. The latter is exemplary chosen as a combination of the
Hosford–Coulomb and Cockcroft–Latham–Oh failure criteria for the high and low
stress triaxiality range, respectively, to cover the wide stress range encountered
in forming. Damage is coupled to elasto-plasticity to capture the damage-induced
degradation of the stiffness and flow stress. This affects the material behaviour
up to failure, thereby realistically altering the stress state. Consequently,
especially for highly ductile materials, where substantial necking and localisation
precede material fracture, the failure prediction is enhanced. The resulting stress
softening is regularised by gradient-enhancement to obtain mesh-objective results.
The analysis of a modified punch test experiment emphasises how the damage-induced
softening effect can strongly alter the actual stress state towards failure. Moreover,
the impact of successful regularisation is shown, and the applicability of the
damage and failure model to clinch joining is proven.
article_number: '106026'
article_type: original
author:
- first_name: Johannes
full_name: Friedlein, Johannes
last_name: Friedlein
- first_name: Julia
full_name: Mergheim, Julia
last_name: Mergheim
- first_name: Paul
full_name: Steinmann, Paul
last_name: Steinmann
citation:
ama: Friedlein J, Mergheim J, Steinmann P. Modelling of stress-state-dependent ductile
damage with gradient-enhancement exemplified for clinch joining. Journal of
the Mechanics and Physics of Solids. 2025;196. doi:10.1016/j.jmps.2025.106026
apa: Friedlein, J., Mergheim, J., & Steinmann, P. (2025). Modelling of stress-state-dependent
ductile damage with gradient-enhancement exemplified for clinch joining. Journal
of the Mechanics and Physics of Solids, 196, Article 106026. https://doi.org/10.1016/j.jmps.2025.106026
bibtex: '@article{Friedlein_Mergheim_Steinmann_2025, title={Modelling of stress-state-dependent
ductile damage with gradient-enhancement exemplified for clinch joining}, volume={196},
DOI={10.1016/j.jmps.2025.106026},
number={106026}, journal={Journal of the Mechanics and Physics of Solids}, publisher={Elsevier
BV}, author={Friedlein, Johannes and Mergheim, Julia and Steinmann, Paul}, year={2025}
}'
chicago: Friedlein, Johannes, Julia Mergheim, and Paul Steinmann. “Modelling of
Stress-State-Dependent Ductile Damage with Gradient-Enhancement Exemplified for
Clinch Joining.” Journal of the Mechanics and Physics of Solids 196 (2025).
https://doi.org/10.1016/j.jmps.2025.106026.
ieee: 'J. Friedlein, J. Mergheim, and P. Steinmann, “Modelling of stress-state-dependent
ductile damage with gradient-enhancement exemplified for clinch joining,” Journal
of the Mechanics and Physics of Solids, vol. 196, Art. no. 106026, 2025, doi:
10.1016/j.jmps.2025.106026.'
mla: Friedlein, Johannes, et al. “Modelling of Stress-State-Dependent Ductile Damage
with Gradient-Enhancement Exemplified for Clinch Joining.” Journal of the Mechanics
and Physics of Solids, vol. 196, 106026, Elsevier BV, 2025, doi:10.1016/j.jmps.2025.106026.
short: J. Friedlein, J. Mergheim, P. Steinmann, Journal of the Mechanics and Physics
of Solids 196 (2025).
date_created: 2025-01-31T17:04:12Z
date_updated: 2025-01-31T17:06:22Z
doi: 10.1016/j.jmps.2025.106026
intvolume: ' 196'
keyword:
- Finite plasticity
- Ductile damage
- Gradient-enhancement
- Stress-state dependency
- Failure
language:
- iso: eng
project:
- _id: '130'
grant_number: '418701707'
name: 'TRR 285: TRR 285: Methodenentwicklung zur mechanischen Fügbarkeit in wandlungsfähigen
Prozessketten'
- _id: '131'
name: 'TRR 285 - A: TRR 285 - Project Area A'
- _id: '139'
name: 'TRR 285 – A05: TRR 285 - Subproject A05'
publication: Journal of the Mechanics and Physics of Solids
publication_identifier:
issn:
- 0022-5096
publication_status: published
publisher: Elsevier BV
status: public
title: Modelling of stress-state-dependent ductile damage with gradient-enhancement
exemplified for clinch joining
type: journal_article
user_id: '84990'
volume: 196
year: '2025'
...
---
_id: '57472'
abstract:
- lang: eng
text: In this paper we introduce, in a Hilbert space setting, a second order dynamical
system with asymptotically vanishing damping and vanishing Tikhonov regularization
that approaches a multiobjective optimization problem with convex and differentiable
components of the objective function. Trajectory solutions are shown to exist
in finite dimensions. We prove fast convergence of the function values, quantified
in terms of a merit function. Based on the regime considered, we establish both
weak and, in some cases, strong convergence of trajectory solutions toward a weak
Pareto optimal solution. To achieve this, we apply Tikhonov regularization individually
to each component of the objective function. This work extends results from single
objective convex optimization into the multiobjective setting.
author:
- first_name: Radu Ioan
full_name: Bot, Radu Ioan
last_name: Bot
- first_name: Konstantin
full_name: Sonntag, Konstantin
id: '56399'
last_name: Sonntag
orcid: https://orcid.org/0000-0003-3384-3496
citation:
ama: Bot RI, Sonntag K. Inertial dynamics with vanishing Tikhonov regularization
for multobjective optimization. Journal of Mathematical Analysis and Applications.
Published online 2025.
apa: Bot, R. I., & Sonntag, K. (2025). Inertial dynamics with vanishing Tikhonov
regularization for multobjective optimization. Journal of Mathematical Analysis
and Applications.
bibtex: '@article{Bot_Sonntag_2025, title={Inertial dynamics with vanishing Tikhonov
regularization for multobjective optimization}, journal={Journal of Mathematical
Analysis and Applications}, author={Bot, Radu Ioan and Sonntag, Konstantin}, year={2025}
}'
chicago: Bot, Radu Ioan, and Konstantin Sonntag. “Inertial Dynamics with Vanishing
Tikhonov Regularization for Multobjective Optimization.” Journal of Mathematical
Analysis and Applications, 2025.
ieee: R. I. Bot and K. Sonntag, “Inertial dynamics with vanishing Tikhonov regularization
for multobjective optimization,” Journal of Mathematical Analysis and Applications,
2025.
mla: Bot, Radu Ioan, and Konstantin Sonntag. “Inertial Dynamics with Vanishing Tikhonov
Regularization for Multobjective Optimization.” Journal of Mathematical Analysis
and Applications, 2025.
short: R.I. Bot, K. Sonntag, Journal of Mathematical Analysis and Applications (2025).
date_created: 2024-11-28T08:58:17Z
date_updated: 2025-10-16T11:56:36Z
ddc:
- '510'
department:
- _id: '101'
- _id: '530'
- _id: '655'
external_id:
arxiv:
- '2411.18422'
file:
- access_level: open_access
content_type: application/pdf
creator: sonntagk
date_created: 2024-11-28T08:58:00Z
date_updated: 2024-11-28T08:58:00Z
file_id: '57473'
file_name: Inertial dynamics with vanishing Tikhonov regularization for multobjective
optimization.pdf
file_size: 4291134
relation: main_file
file_date_updated: 2024-11-28T08:58:00Z
has_accepted_license: '1'
keyword:
- Pareto optimization
- Lyapunov analysis
- gradient-like dynamical systems
- inertial dynamics
- asymptotic vanishing damping
- Tikhonov regularization
- strong convergence
language:
- iso: eng
main_file_link:
- url: https://arxiv.org/pdf/2411.18422
oa: '1'
publication: Journal of Mathematical Analysis and Applications
status: public
title: Inertial dynamics with vanishing Tikhonov regularization for multobjective
optimization
type: journal_article
user_id: '56399'
year: '2025'
...
---
_id: '32447'
abstract:
- lang: eng
text: 'We present a new gradient-like dynamical system related to unconstrained
convex smooth multiobjective optimization which involves inertial effects and
asymptotic vanishing damping. To the best of our knowledge, this system is the
first inertial gradient-like system for multiobjective optimization problems including
asymptotic vanishing damping, expanding the ideas previously laid out in [H. Attouch
and G. Garrigos, Multiobjective Optimization: An Inertial Dynamical Approach to
Pareto Optima, preprint, arXiv:1506.02823, 2015]. We prove existence of solutions
to this system in finite dimensions and further prove that its bounded solutions
converge weakly to weakly Pareto optimal points. In addition, we obtain a convergence
rate of order \(\mathcal{O}(t^{-2})\) for the function values measured with a
merit function. This approach presents a good basis for the development of fast
gradient methods for multiobjective optimization.'
article_type: original
author:
- first_name: Konstantin
full_name: Sonntag, Konstantin
id: '56399'
last_name: Sonntag
orcid: https://orcid.org/0000-0003-3384-3496
- first_name: Sebastian
full_name: Peitz, Sebastian
id: '47427'
last_name: Peitz
orcid: 0000-0002-3389-793X
citation:
ama: Sonntag K, Peitz S. Fast Convergence of Inertial Multiobjective Gradient-Like
Systems with Asymptotic Vanishing Damping. SIAM Journal on Optimization.
2024;34(3):2259-2286. doi:10.1137/23M1588512
apa: Sonntag, K., & Peitz, S. (2024). Fast Convergence of Inertial Multiobjective
Gradient-Like Systems with Asymptotic Vanishing Damping. SIAM Journal on Optimization,
34(3), 2259–2286. https://doi.org/10.1137/23M1588512
bibtex: '@article{Sonntag_Peitz_2024, title={Fast Convergence of Inertial Multiobjective
Gradient-Like Systems with Asymptotic Vanishing Damping}, volume={34}, DOI={10.1137/23M1588512}, number={3},
journal={SIAM Journal on Optimization}, publisher={Society for Industrial and
Applied Mathematics}, author={Sonntag, Konstantin and Peitz, Sebastian}, year={2024},
pages={2259–2286} }'
chicago: 'Sonntag, Konstantin, and Sebastian Peitz. “Fast Convergence of Inertial
Multiobjective Gradient-Like Systems with Asymptotic Vanishing Damping.” SIAM
Journal on Optimization 34, no. 3 (2024): 2259–86. https://doi.org/10.1137/23M1588512.'
ieee: 'K. Sonntag and S. Peitz, “Fast Convergence of Inertial Multiobjective Gradient-Like
Systems with Asymptotic Vanishing Damping,” SIAM Journal on Optimization,
vol. 34, no. 3, pp. 2259–2286, 2024, doi: 10.1137/23M1588512.'
mla: Sonntag, Konstantin, and Sebastian Peitz. “Fast Convergence of Inertial Multiobjective
Gradient-Like Systems with Asymptotic Vanishing Damping.” SIAM Journal on Optimization,
vol. 34, no. 3, Society for Industrial and Applied Mathematics, 2024, pp. 2259–86,
doi:10.1137/23M1588512.
short: K. Sonntag, S. Peitz, SIAM Journal on Optimization 34 (2024) 2259–2286.
date_created: 2022-07-28T11:53:02Z
date_updated: 2024-07-02T09:27:39Z
department:
- _id: '101'
- _id: '655'
doi: 10.1137/23M1588512
intvolume: ' 34'
issue: '3'
keyword:
- multiobjective optimization
- Pareto optimization
- Lyapunov analysis
- gradient-likedynamical systems
- inertial dynamics
- asymptotic vanishing damping
- fast convergence
language:
- iso: eng
page: 2259 - 2286
publication: SIAM Journal on Optimization
publication_identifier:
issn:
- 1095-7189
publication_status: published
publisher: Society for Industrial and Applied Mathematics
status: public
title: Fast Convergence of Inertial Multiobjective Gradient-Like Systems with Asymptotic
Vanishing Damping
type: journal_article
user_id: '56399'
volume: 34
year: '2024'
...
---
_id: '58491'
abstract:
- lang: eng
text: Similar to bulk metal forming, clinch joining is characterised by
large plastic deformations and a variety of different 3D stress states, including
severe compression. However, inherent to plastic forming is the nucleation and
growth of defects, whose detrimental effects on the material behaviour can be
described by continuum damage models and eventually lead to material failure.
As the damage evolution strongly depends on the stress state, a stress-state-dependent
model is utilised to correctly track the accumulation. To formulate and parameterise
this model, besides classical experiments, so-called modified punch tests are
also integrated herein to enhance the calibration of the failure model by capturing
a larger range of stress states and metal-forming-specific loading conditions.
Moreover, when highly ductile materials are considered, such as the dual-phase
steel HCT590X and the aluminium alloy EN AW-6014 T4 investigated here, strong
necking and localisation might occur prior to fracture. This can alter the stress
state and affect the actual strain at failure. This influence is captured by coupling
plasticity and damage to incorporate the damage-induced softening effect. Its
relative importance is shown by conducting inverse parameter identifications to
determine damage and failure parameters for both mentioned ductile metals based
on up to 12 different experiments.
article_number: '157'
author:
- first_name: Johannes
full_name: Friedlein, Johannes
last_name: Friedlein
- first_name: Max
full_name: Böhnke, Max
last_name: Böhnke
- first_name: Malte
full_name: Schlichter, Malte
last_name: Schlichter
- first_name: Mathias
full_name: Bobbert, Mathias
last_name: Bobbert
- first_name: Gerson
full_name: Meschut, Gerson
last_name: Meschut
- first_name: Julia
full_name: Mergheim, Julia
last_name: Mergheim
- first_name: Paul
full_name: Steinmann, Paul
last_name: Steinmann
citation:
ama: Friedlein J, Böhnke M, Schlichter M, et al. Material Parameter Identification
for a Stress-State-Dependent Ductile Damage and Failure Model Applied to Clinch
Joining. Journal of Manufacturing and Materials Processing. 2024;8(4).
doi:10.3390/jmmp8040157
apa: Friedlein, J., Böhnke, M., Schlichter, M., Bobbert, M., Meschut, G., Mergheim,
J., & Steinmann, P. (2024). Material Parameter Identification for a Stress-State-Dependent
Ductile Damage and Failure Model Applied to Clinch Joining. Journal of Manufacturing
and Materials Processing, 8(4), Article 157. https://doi.org/10.3390/jmmp8040157
bibtex: '@article{Friedlein_Böhnke_Schlichter_Bobbert_Meschut_Mergheim_Steinmann_2024,
title={Material Parameter Identification for a Stress-State-Dependent Ductile
Damage and Failure Model Applied to Clinch Joining}, volume={8}, DOI={10.3390/jmmp8040157},
number={4157}, journal={Journal of Manufacturing and Materials Processing}, publisher={MDPI
AG}, author={Friedlein, Johannes and Böhnke, Max and Schlichter, Malte and Bobbert,
Mathias and Meschut, Gerson and Mergheim, Julia and Steinmann, Paul}, year={2024}
}'
chicago: Friedlein, Johannes, Max Böhnke, Malte Schlichter, Mathias Bobbert, Gerson
Meschut, Julia Mergheim, and Paul Steinmann. “Material Parameter Identification
for a Stress-State-Dependent Ductile Damage and Failure Model Applied to Clinch
Joining.” Journal of Manufacturing and Materials Processing 8, no. 4 (2024).
https://doi.org/10.3390/jmmp8040157.
ieee: 'J. Friedlein et al., “Material Parameter Identification for a Stress-State-Dependent
Ductile Damage and Failure Model Applied to Clinch Joining,” Journal of Manufacturing
and Materials Processing, vol. 8, no. 4, Art. no. 157, 2024, doi: 10.3390/jmmp8040157.'
mla: Friedlein, Johannes, et al. “Material Parameter Identification for a Stress-State-Dependent
Ductile Damage and Failure Model Applied to Clinch Joining.” Journal of Manufacturing
and Materials Processing, vol. 8, no. 4, 157, MDPI AG, 2024, doi:10.3390/jmmp8040157.
short: J. Friedlein, M. Böhnke, M. Schlichter, M. Bobbert, G. Meschut, J. Mergheim,
P. Steinmann, Journal of Manufacturing and Materials Processing 8 (2024).
date_created: 2025-01-31T16:59:13Z
date_updated: 2025-01-31T17:03:34Z
doi: 10.3390/jmmp8040157
intvolume: ' 8'
issue: '4'
keyword:
- ductile damage
- stress-state dependency
- failure
- parameter identification
- punch test
- clinching
language:
- iso: eng
project:
- _id: '130'
grant_number: '418701707'
name: 'TRR 285: TRR 285: Methodenentwicklung zur mechanischen Fügbarkeit in wandlungsfähigen
Prozessketten'
- _id: '131'
name: 'TRR 285 - A: TRR 285 - Project Area A'
- _id: '139'
name: 'TRR 285 – A05: TRR 285 - Subproject A05'
publication: Journal of Manufacturing and Materials Processing
publication_identifier:
issn:
- 2504-4494
publication_status: published
publisher: MDPI AG
status: public
title: Material Parameter Identification for a Stress-State-Dependent Ductile Damage
and Failure Model Applied to Clinch Joining
type: journal_article
user_id: '84990'
volume: 8
year: '2024'
...
---
_id: '56097'
abstract:
- lang: eng
text: We contrast different gradient-enhancements for plasticity-damage material
models in the logarithmic strain space and compare them to reference models based
on multiplicative plasticity. The models being compared include plasticity - gradient-damage,
where the gradient-enhancement is applied on the local damage variable, and gradient-plasticity
- damage with a gradient-enhanced plastic hardening variable. Thereby, gradient-plasticity
proved to be able to simultaneously regularise plastic and ductile (plasticity-driven)
damage localisation as confirmed by numerical localisation analyses. This appears
to be especially advantageous for logarithmic strain space plasticity-damage,
because of the observed plastic localisation even for the case of plasticity with
hardening. Even though gradient-plasticity appears to be numerically more demanding,
two numerical examples indicate a good robustness and mesh objectivity in the
softening regime. Moreover, the internal length for plasticity is able to adjust
the damage zone width, similarly to gradient-damage, however ensuring a priori
that damage takes place exclusively inside the plastic zone.
article_number: '104946'
article_type: original
author:
- first_name: Johannes
full_name: Friedlein, Johannes
last_name: Friedlein
- first_name: Julia
full_name: Mergheim, Julia
last_name: Mergheim
- first_name: Paul
full_name: Steinmann, Paul
last_name: Steinmann
citation:
ama: Friedlein J, Mergheim J, Steinmann P. Efficient gradient enhancements for plasticity
with ductile damage in the logarithmic strain space. European Journal of Mechanics
- A/Solids. 2023;99. doi:10.1016/j.euromechsol.2023.104946
apa: Friedlein, J., Mergheim, J., & Steinmann, P. (2023). Efficient gradient
enhancements for plasticity with ductile damage in the logarithmic strain space.
European Journal of Mechanics - A/Solids, 99, Article 104946. https://doi.org/10.1016/j.euromechsol.2023.104946
bibtex: '@article{Friedlein_Mergheim_Steinmann_2023, title={Efficient gradient enhancements
for plasticity with ductile damage in the logarithmic strain space}, volume={99},
DOI={10.1016/j.euromechsol.2023.104946},
number={104946}, journal={European Journal of Mechanics - A/Solids}, publisher={Elsevier
BV}, author={Friedlein, Johannes and Mergheim, Julia and Steinmann, Paul}, year={2023}
}'
chicago: Friedlein, Johannes, Julia Mergheim, and Paul Steinmann. “Efficient Gradient
Enhancements for Plasticity with Ductile Damage in the Logarithmic Strain Space.”
European Journal of Mechanics - A/Solids 99 (2023). https://doi.org/10.1016/j.euromechsol.2023.104946.
ieee: 'J. Friedlein, J. Mergheim, and P. Steinmann, “Efficient gradient enhancements
for plasticity with ductile damage in the logarithmic strain space,” European
Journal of Mechanics - A/Solids, vol. 99, Art. no. 104946, 2023, doi: 10.1016/j.euromechsol.2023.104946.'
mla: Friedlein, Johannes, et al. “Efficient Gradient Enhancements for Plasticity
with Ductile Damage in the Logarithmic Strain Space.” European Journal of Mechanics
- A/Solids, vol. 99, 104946, Elsevier BV, 2023, doi:10.1016/j.euromechsol.2023.104946.
short: J. Friedlein, J. Mergheim, P. Steinmann, European Journal of Mechanics -
A/Solids 99 (2023).
date_created: 2024-09-10T15:23:49Z
date_updated: 2026-02-24T14:37:05Z
doi: 10.1016/j.euromechsol.2023.104946
intvolume: ' 99'
keyword:
- Finite plasticity
- Logarithmic strain space
- Ductile damage
- Gradient-enhancement
- Gradient-plasticity
- Gradient-damage
- Loss of ellipticity
language:
- iso: eng
project:
- _id: '130'
name: 'TRR 285: TRR 285'
- _id: '131'
name: 'TRR 285 - A: TRR 285 - Project Area A'
- _id: '139'
name: 'TRR 285 – A05: TRR 285 - Subproject A05'
- _id: '130'
name: 'TRR 285: Methodenentwicklung zur mechanischen Fügbarkeit in wandlungsfähigen
Prozessketten'
publication: European Journal of Mechanics - A/Solids
publication_identifier:
issn:
- 0997-7538
publication_status: published
publisher: Elsevier BV
status: public
title: Efficient gradient enhancements for plasticity with ductile damage in the logarithmic
strain space
type: journal_article
user_id: '84990'
volume: 99
year: '2023'
...
---
_id: '27186'
abstract:
- lang: eng
text: 'The presented paper aims to characterize the damage and fracture behavior
of HX340LAD Micro-Alloyed steels using small punch test. Variations with respect
to punch geometries and cutting clearance are made to describe the damage behavior
of the material under different loading conditions. Experimental investigations
are conducted to identify the crack initiation in the specimens. Furthermore,
the numerical FEM simulations are performed to identify the stress state at crack
initiation. It is shown that different stress states from shear to biaxial tension
can be achieved by changing the geometries of punch and varying the cutting clearance.
Moreover, it is presented how changing the configurations can influence the stress
state variables: Triaxiality and lode angle parameter.'
article_type: original
author:
- first_name: Mortaza
full_name: Otroshi, Mortaza
id: '71269'
last_name: Otroshi
orcid: 0000-0002-8652-9209
- first_name: Gerson
full_name: Meschut, Gerson
id: '32056'
last_name: Meschut
orcid: 0000-0002-2763-1246
citation:
ama: Otroshi M, Meschut G. Influence of cutting clearance and punch geometry on
the stress state in small punch test . Engineering Failure Analysis. 2022;136(c).
doi:10.1016/j.engfailanal.2022.106183
apa: Otroshi, M., & Meschut, G. (2022). Influence of cutting clearance and punch
geometry on the stress state in small punch test . Engineering Failure Analysis,
136(c). https://doi.org/10.1016/j.engfailanal.2022.106183
bibtex: '@article{Otroshi_Meschut_2022, title={Influence of cutting clearance and
punch geometry on the stress state in small punch test }, volume={136}, DOI={10.1016/j.engfailanal.2022.106183},
number={c}, journal={Engineering Failure Analysis}, publisher={Elsevier}, author={Otroshi,
Mortaza and Meschut, Gerson}, year={2022} }'
chicago: Otroshi, Mortaza, and Gerson Meschut. “Influence of Cutting Clearance and
Punch Geometry on the Stress State in Small Punch Test .” Engineering Failure
Analysis 136, no. c (2022). https://doi.org/10.1016/j.engfailanal.2022.106183.
ieee: 'M. Otroshi and G. Meschut, “Influence of cutting clearance and punch geometry
on the stress state in small punch test ,” Engineering Failure Analysis,
vol. 136, no. c, 2022, doi: 10.1016/j.engfailanal.2022.106183.'
mla: Otroshi, Mortaza, and Gerson Meschut. “Influence of Cutting Clearance and Punch
Geometry on the Stress State in Small Punch Test .” Engineering Failure Analysis,
vol. 136, no. c, Elsevier, 2022, doi:10.1016/j.engfailanal.2022.106183.
short: M. Otroshi, G. Meschut, Engineering Failure Analysis 136 (2022).
date_created: 2021-11-07T20:34:51Z
date_updated: 2022-04-25T07:48:20Z
department:
- _id: '157'
doi: 10.1016/j.engfailanal.2022.106183
intvolume: ' 136'
issue: c
keyword:
- Ductile damage
- stress state
- small punch test
- triaxiality
- lode angle parameter
language:
- iso: eng
publication: Engineering Failure Analysis
publication_identifier:
issn:
- 1350-6307
publication_status: published
publisher: Elsevier
quality_controlled: '1'
status: public
title: 'Influence of cutting clearance and punch geometry on the stress state in small
punch test '
type: journal_article
user_id: '71269'
volume: 136
year: '2022'
...
---
_id: '34209'
abstract:
- lang: eng
text: Predicting the durability of components subjected to mechanical load under
environmental conditions leading to corrosion is one of the most challenging tasks
in mechanical engineering. The demand for precise predictions increases with the
desire of lightweight design in transportation due to environmental protection.
Corrosion with its manifold of mechanisms often occurs together with the production
of hydrogen by electrochemical reactions. Hydrogen embrittlement is one of the
most feared damage mechanisms for metal constructions often leading to early and
unexpected failure. Until now, predictions are mostly based on costly experiments.
Hence, a rational predictive model based on the fundamentals of electrochemistry
and damage mechanics has to be developed in order to reduce the costs. In this
work, a first model approach based on classical continuum damage mechanics is
presented to couple both, the damage induced by the mechanical stress and the
hydrogen embrittlement. An elaborated two-scale model based on the selfconsistent
theory is applied to describe the mechanical damage due to fatigue. The electrochemical
kinetics are elucidated through the Langmuir adsorption isotherm and the diffusion
equation to consider the impact of hydrogen embrittlement on the fatigue. The
modeling of the mechanism of hydrogen embrittlement defines the progress of damage
accumulation due to the electrochemistry. The durability results like the S-N
diagram show the influence of hydrogen embrittlement by varying, e.g. the fatigue
frequency or the stress ratio.
author:
- first_name: Yuhao
full_name: Shi, Yuhao
last_name: Shi
- first_name: Sven
full_name: Harzheim, Sven
last_name: Harzheim
- first_name: Martin
full_name: Hofmann, Martin
last_name: Hofmann
- first_name: Thomas
full_name: Wallmersperger, Thomas
last_name: Wallmersperger
citation:
ama: 'Shi Y, Harzheim S, Hofmann M, Wallmersperger T. A Damage Model for Corrosion
Fatigue Due to Hydrogen Embrittlement. In: Material Modeling and Structural
Mechanics. Springer International Publishing; 2022. doi:10.1007/978-3-030-97675-0_9'
apa: Shi, Y., Harzheim, S., Hofmann, M., & Wallmersperger, T. (2022). A Damage
Model for Corrosion Fatigue Due to Hydrogen Embrittlement. In Material Modeling
and Structural Mechanics. Springer International Publishing. https://doi.org/10.1007/978-3-030-97675-0_9
bibtex: '@inbook{Shi_Harzheim_Hofmann_Wallmersperger_2022, place={Cham}, title={A
Damage Model for Corrosion Fatigue Due to Hydrogen Embrittlement}, DOI={10.1007/978-3-030-97675-0_9},
booktitle={Material Modeling and Structural Mechanics}, publisher={Springer International
Publishing}, author={Shi, Yuhao and Harzheim, Sven and Hofmann, Martin and Wallmersperger,
Thomas}, year={2022} }'
chicago: 'Shi, Yuhao, Sven Harzheim, Martin Hofmann, and Thomas Wallmersperger.
“A Damage Model for Corrosion Fatigue Due to Hydrogen Embrittlement.” In Material
Modeling and Structural Mechanics. Cham: Springer International Publishing,
2022. https://doi.org/10.1007/978-3-030-97675-0_9.'
ieee: 'Y. Shi, S. Harzheim, M. Hofmann, and T. Wallmersperger, “A Damage Model for
Corrosion Fatigue Due to Hydrogen Embrittlement,” in Material Modeling and
Structural Mechanics, Cham: Springer International Publishing, 2022.'
mla: Shi, Yuhao, et al. “A Damage Model for Corrosion Fatigue Due to Hydrogen Embrittlement.”
Material Modeling and Structural Mechanics, Springer International Publishing,
2022, doi:10.1007/978-3-030-97675-0_9.
short: 'Y. Shi, S. Harzheim, M. Hofmann, T. Wallmersperger, in: Material Modeling
and Structural Mechanics, Springer International Publishing, Cham, 2022.'
date_created: 2022-12-05T20:53:13Z
date_updated: 2023-01-02T11:10:26Z
department:
- _id: '630'
doi: 10.1007/978-3-030-97675-0_9
keyword:
- Hydrogen embrittlement
- Fatigue
- Continuum damage mechanics
- Numerical simulation
- Multi-field problem
language:
- iso: eng
place: Cham
project:
- _id: '130'
grant_number: '418701707'
name: 'TRR 285: TRR 285'
- _id: '132'
name: 'TRR 285 - B: TRR 285 - Project Area B'
- _id: '142'
name: 'TRR 285 – B03: TRR 285 - Subproject B03'
publication: Material Modeling and Structural Mechanics
publication_identifier:
isbn:
- '9783030976743'
- '9783030976750'
issn:
- 1869-8433
- 1869-8441
publication_status: published
publisher: Springer International Publishing
status: public
title: A Damage Model for Corrosion Fatigue Due to Hydrogen Embrittlement
type: book_chapter
user_id: '14931'
year: '2022'
...
---
_id: '25476'
abstract:
- lang: eng
text: This study deals with the damage behavior of metallic materials by the application
of different manufacturing processes and using different optical measurement methods
to identify the crack initiation in the damage specimen. The study is intended
to highlight the importance of considering manufacturing processes and optical
measurement methods in a numerical simulation when analyzing the damage behavior
of metallic materials. To describe the damage behavior of the material in the
process chain simulations, it is important to calibrate the parameters of damage
model more accurately. These parameters are determined using experimental investigation
of desired damage specimens. In this regard, a selected damage specimen manufactured
by different cutting processes is first experimentally and then numerically investigated.
It is shown that the manufacturing process and the optical measurement methods
influence the stress state analyzed in the numerical simulation.
article_type: original
author:
- first_name: Mortaza
full_name: Otroshi, Mortaza
id: '71269'
last_name: Otroshi
orcid: 0000-0002-8652-9209
- first_name: Gerson
full_name: Meschut, Gerson
id: '32056'
last_name: Meschut
orcid: 0000-0002-2763-1246
- first_name: Aathavan
full_name: Nesakumar, Aathavan
last_name: Nesakumar
citation:
ama: Otroshi M, Meschut G, Nesakumar A. The influence of manufacturing processes
and optical measurement methods on the damage behavior of HX340LAD micro-alloyed
steels. Journal of Manufacturing Engineering. 2021;16(3):70-76. doi:https://doi.org/10.37255/jme.v16i3pp070-076
apa: Otroshi, M., Meschut, G., & Nesakumar, A. (2021). The influence of manufacturing
processes and optical measurement methods on the damage behavior of HX340LAD micro-alloyed
steels. Journal of Manufacturing Engineering, 16(3), 70–76. https://doi.org/10.37255/jme.v16i3pp070-076
bibtex: '@article{Otroshi_Meschut_Nesakumar_2021, title={The influence of manufacturing
processes and optical measurement methods on the damage behavior of HX340LAD micro-alloyed
steels}, volume={16}, DOI={https://doi.org/10.37255/jme.v16i3pp070-076},
number={3}, journal={Journal of Manufacturing Engineering}, author={Otroshi, Mortaza
and Meschut, Gerson and Nesakumar, Aathavan}, year={2021}, pages={70–76} }'
chicago: 'Otroshi, Mortaza, Gerson Meschut, and Aathavan Nesakumar. “The Influence
of Manufacturing Processes and Optical Measurement Methods on the Damage Behavior
of HX340LAD Micro-Alloyed Steels.” Journal of Manufacturing Engineering
16, no. 3 (2021): 70–76. https://doi.org/10.37255/jme.v16i3pp070-076.'
ieee: 'M. Otroshi, G. Meschut, and A. Nesakumar, “The influence of manufacturing
processes and optical measurement methods on the damage behavior of HX340LAD micro-alloyed
steels,” Journal of Manufacturing Engineering, vol. 16, no. 3, pp. 70–76,
2021, doi: https://doi.org/10.37255/jme.v16i3pp070-076.'
mla: Otroshi, Mortaza, et al. “The Influence of Manufacturing Processes and Optical
Measurement Methods on the Damage Behavior of HX340LAD Micro-Alloyed Steels.”
Journal of Manufacturing Engineering, vol. 16, no. 3, 2021, pp. 70–76,
doi:https://doi.org/10.37255/jme.v16i3pp070-076.
short: M. Otroshi, G. Meschut, A. Nesakumar, Journal of Manufacturing Engineering
16 (2021) 70–76.
date_created: 2021-10-05T09:11:47Z
date_updated: 2022-04-25T07:48:07Z
department:
- _id: '157'
doi: https://doi.org/10.37255/jme.v16i3pp070-076
intvolume: ' 16'
issue: '3'
keyword:
- Damage behaviour
- Stress triaxiality
- Manufacturing process and Optical measurement
language:
- iso: eng
main_file_link:
- open_access: '1'
url: http://smenec.org/index.php/1/article/view/187
oa: '1'
page: 70-76
publication: Journal of Manufacturing Engineering
publication_status: published
quality_controlled: '1'
status: public
title: The influence of manufacturing processes and optical measurement methods on
the damage behavior of HX340LAD micro-alloyed steels
type: journal_article
user_id: '71269'
volume: 16
year: '2021'
...
---
_id: '20143'
author:
- first_name: Mortaza
full_name: Otroshi, Mortaza
id: '71269'
last_name: Otroshi
orcid: 0000-0002-8652-9209
- first_name: Moritz
full_name: Rossel, Moritz
last_name: Rossel
- first_name: Gerson
full_name: Meschut, Gerson
id: '32056'
last_name: Meschut
orcid: 0000-0002-2763-1246
citation:
ama: Otroshi M, Rossel M, Meschut G. Stress state dependent damage modeling of self-pierce
riveting process simulation using GISSMO damage model. Journal of Advanced
Joining Processes. 2020;1. doi:10.1016/j.jajp.2020.100015
apa: Otroshi, M., Rossel, M., & Meschut, G. (2020). Stress state dependent damage
modeling of self-pierce riveting process simulation using GISSMO damage model.
Journal of Advanced Joining Processes, 1. https://doi.org/10.1016/j.jajp.2020.100015
bibtex: '@article{Otroshi_Rossel_Meschut_2020, title={Stress state dependent damage
modeling of self-pierce riveting process simulation using GISSMO damage model},
volume={1}, DOI={10.1016/j.jajp.2020.100015},
journal={Journal of Advanced Joining Processes}, publisher={Elsevier}, author={Otroshi,
Mortaza and Rossel, Moritz and Meschut, Gerson}, year={2020} }'
chicago: Otroshi, Mortaza, Moritz Rossel, and Gerson Meschut. “Stress State Dependent
Damage Modeling of Self-Pierce Riveting Process Simulation Using GISSMO Damage
Model.” Journal of Advanced Joining Processes 1 (2020). https://doi.org/10.1016/j.jajp.2020.100015.
ieee: 'M. Otroshi, M. Rossel, and G. Meschut, “Stress state dependent damage modeling
of self-pierce riveting process simulation using GISSMO damage model,” Journal
of Advanced Joining Processes, vol. 1, 2020, doi: 10.1016/j.jajp.2020.100015.'
mla: Otroshi, Mortaza, et al. “Stress State Dependent Damage Modeling of Self-Pierce
Riveting Process Simulation Using GISSMO Damage Model.” Journal of Advanced
Joining Processes, vol. 1, Elsevier, 2020, doi:10.1016/j.jajp.2020.100015.
short: M. Otroshi, M. Rossel, G. Meschut, Journal of Advanced Joining Processes
1 (2020).
date_created: 2020-10-20T14:49:15Z
date_updated: 2022-04-25T07:49:50Z
department:
- _id: '157'
doi: 10.1016/j.jajp.2020.100015
intvolume: ' 1'
keyword:
- Self-pierce riveting
- Ductile fracture
- Damage modeling
- GISSMO damage model
language:
- iso: eng
main_file_link:
- open_access: '1'
oa: '1'
publication: Journal of Advanced Joining Processes
publisher: Elsevier
quality_controlled: '1'
status: public
title: Stress state dependent damage modeling of self-pierce riveting process simulation
using GISSMO damage model
type: journal_article
user_id: '71269'
volume: 1
year: '2020'
...
---
_id: '11927'
abstract:
- lang: eng
text: Maximizing the output signal-to-noise ratio (SNR) of a sensor array in the
presence of spatially colored noise leads to a generalized eigenvalue problem.
While this approach has extensively been employed in narrowband (antenna) array
beamforming, it is typically not used for broadband (microphone) array beamforming
due to the uncontrolled amount of speech distortion introduced by a narrowband
SNR criterion. In this paper, we show how the distortion of the desired signal
can be controlled by a single-channel post-filter, resulting in a performance
comparable to the generalized minimum variance distortionless response beamformer,
where arbitrary transfer functions relate the source and the microphones. Results
are given both for directional and diffuse noise. A novel gradient ascent adaptation
algorithm is presented, and its good convergence properties are experimentally
revealed by comparison with alternatives from the literature. A key feature of
the proposed beamformer is that it operates blindly, i.e., it neither requires
knowledge about the array geometry nor an explicit estimation of the transfer
functions from source to sensors or the direction-of-arrival.
author:
- first_name: Ernst
full_name: Warsitz, Ernst
last_name: Warsitz
- first_name: Reinhold
full_name: Haeb-Umbach, Reinhold
id: '242'
last_name: Haeb-Umbach
citation:
ama: Warsitz E, Haeb-Umbach R. Blind Acoustic Beamforming Based on Generalized Eigenvalue
Decomposition. IEEE Transactions on Audio, Speech, and Language Processing.
2007;15(5):1529-1539. doi:10.1109/TASL.2007.898454
apa: Warsitz, E., & Haeb-Umbach, R. (2007). Blind Acoustic Beamforming Based
on Generalized Eigenvalue Decomposition. IEEE Transactions on Audio, Speech,
and Language Processing, 15(5), 1529–1539. https://doi.org/10.1109/TASL.2007.898454
bibtex: '@article{Warsitz_Haeb-Umbach_2007, title={Blind Acoustic Beamforming Based
on Generalized Eigenvalue Decomposition}, volume={15}, DOI={10.1109/TASL.2007.898454},
number={5}, journal={IEEE Transactions on Audio, Speech, and Language Processing},
author={Warsitz, Ernst and Haeb-Umbach, Reinhold}, year={2007}, pages={1529–1539}
}'
chicago: 'Warsitz, Ernst, and Reinhold Haeb-Umbach. “Blind Acoustic Beamforming
Based on Generalized Eigenvalue Decomposition.” IEEE Transactions on Audio,
Speech, and Language Processing 15, no. 5 (2007): 1529–39. https://doi.org/10.1109/TASL.2007.898454.'
ieee: E. Warsitz and R. Haeb-Umbach, “Blind Acoustic Beamforming Based on Generalized
Eigenvalue Decomposition,” IEEE Transactions on Audio, Speech, and Language
Processing, vol. 15, no. 5, pp. 1529–1539, 2007.
mla: Warsitz, Ernst, and Reinhold Haeb-Umbach. “Blind Acoustic Beamforming Based
on Generalized Eigenvalue Decomposition.” IEEE Transactions on Audio, Speech,
and Language Processing, vol. 15, no. 5, 2007, pp. 1529–39, doi:10.1109/TASL.2007.898454.
short: E. Warsitz, R. Haeb-Umbach, IEEE Transactions on Audio, Speech, and Language
Processing 15 (2007) 1529–1539.
date_created: 2019-07-12T05:30:57Z
date_updated: 2022-01-06T06:51:12Z
department:
- _id: '54'
doi: 10.1109/TASL.2007.898454
intvolume: ' 15'
issue: '5'
keyword:
- acoustic signal processing
- arbitrary transfer function
- array signal processing
- blind acoustic beamforming
- direction-of-arrival
- direction-of-arrival estimation
- eigenvalues and eigenfunctions
- generalized eigenvalue decomposition
- gradient ascent adaptation algorithm
- microphone arrays
- microphones
- narrowband array beamforming
- sensor array
- single-channel post-filter
- spatially colored noise
- transfer functions
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://groups.uni-paderborn.de/nt/pubs/2007/WaHa07.pdf
oa: '1'
page: 1529-1539
publication: IEEE Transactions on Audio, Speech, and Language Processing
status: public
title: Blind Acoustic Beamforming Based on Generalized Eigenvalue Decomposition
type: journal_article
user_id: '44006'
volume: 15
year: '2007'
...
---
_id: '11930'
abstract:
- lang: eng
text: For human-machine interfaces in distant-talking environments multichannel
signal processing is often employed to obtain an enhanced signal for subsequent
processing. In this paper we propose a novel adaptation algorithm for a filter-and-sum
beamformer to adjust the coefficients of FIR filters to changing acoustic room
impulses, e.g. due to speaker movement. A deterministic and a stochastic gradient
ascent algorithm are derived from a constrained optimization problem, which iteratively
estimates the eigenvector corresponding to the largest eigenvalue of the cross
power spectral density of the microphone signals. The method does not require
an explicit estimation of the speaker location. The experimental results show
fast adaptation and excellent robustness of the proposed algorithm.
author:
- first_name: Ernst
full_name: Warsitz, Ernst
last_name: Warsitz
- first_name: Reinhold
full_name: Haeb-Umbach, Reinhold
id: '242'
last_name: Haeb-Umbach
citation:
ama: 'Warsitz E, Haeb-Umbach R. Acoustic filter-and-sum beamforming by adaptive
principal component analysis. In: IEEE International Conference on Acoustics,
Speech and Signal Processing (ICASSP 2005). Vol 4. ; 2005:iv/797-iv/800 Vol.
4. doi:10.1109/ICASSP.2005.1416129'
apa: Warsitz, E., & Haeb-Umbach, R. (2005). Acoustic filter-and-sum beamforming
by adaptive principal component analysis. In IEEE International Conference
on Acoustics, Speech and Signal Processing (ICASSP 2005) (Vol. 4, p. iv/797-iv/800
Vol. 4). https://doi.org/10.1109/ICASSP.2005.1416129
bibtex: '@inproceedings{Warsitz_Haeb-Umbach_2005, title={Acoustic filter-and-sum
beamforming by adaptive principal component analysis}, volume={4}, DOI={10.1109/ICASSP.2005.1416129},
booktitle={IEEE International Conference on Acoustics, Speech and Signal Processing
(ICASSP 2005)}, author={Warsitz, Ernst and Haeb-Umbach, Reinhold}, year={2005},
pages={iv/797-iv/800 Vol. 4} }'
chicago: Warsitz, Ernst, and Reinhold Haeb-Umbach. “Acoustic Filter-and-Sum Beamforming
by Adaptive Principal Component Analysis.” In IEEE International Conference
on Acoustics, Speech and Signal Processing (ICASSP 2005), 4:iv/797-iv/800
Vol. 4, 2005. https://doi.org/10.1109/ICASSP.2005.1416129.
ieee: E. Warsitz and R. Haeb-Umbach, “Acoustic filter-and-sum beamforming by adaptive
principal component analysis,” in IEEE International Conference on Acoustics,
Speech and Signal Processing (ICASSP 2005), 2005, vol. 4, p. iv/797-iv/800
Vol. 4.
mla: Warsitz, Ernst, and Reinhold Haeb-Umbach. “Acoustic Filter-and-Sum Beamforming
by Adaptive Principal Component Analysis.” IEEE International Conference on
Acoustics, Speech and Signal Processing (ICASSP 2005), vol. 4, 2005, p. iv/797-iv/800
Vol. 4, doi:10.1109/ICASSP.2005.1416129.
short: 'E. Warsitz, R. Haeb-Umbach, in: IEEE International Conference on Acoustics,
Speech and Signal Processing (ICASSP 2005), 2005, p. iv/797-iv/800 Vol. 4.'
date_created: 2019-07-12T05:31:00Z
date_updated: 2022-01-06T06:51:12Z
department:
- _id: '54'
doi: 10.1109/ICASSP.2005.1416129
intvolume: ' 4'
keyword:
- acoustic filter-and-sum beamforming
- acoustic room impulses
- acoustic signal processing
- adaptive principal component analysis
- adaptive signal processing
- architectural acoustics
- constrained optimization problem
- cross power spectral density
- deterministic algorithm
- deterministic algorithms
- distant-talking environments
- eigenvalues and eigenfunctions
- eigenvector
- enhanced signal
- filter-and-sum beamformer
- FIR filter coefficients
- FIR filter coefficients
- FIR filters
- gradient methods
- human-machine interfaces
- iterative estimation
- iterative methods
- largest eigenvalue
- microphone signals
- multichannel signal processing
- optimisation
- principal component analysis
- spectral analysis
- stochastic gradient ascent algorithm
- stochastic processes
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://groups.uni-paderborn.de/nt/pubs/2005/WaHa05.pdf
oa: '1'
page: iv/797-iv/800 Vol. 4
publication: IEEE International Conference on Acoustics, Speech and Signal Processing
(ICASSP 2005)
status: public
title: Acoustic filter-and-sum beamforming by adaptive principal component analysis
type: conference
user_id: '44006'
volume: 4
year: '2005'
...