@article{64251, abstract = {{ABSTRACT Clinching is a widely adopted joining technique in the automotive industry, enabling the fabrication of lightweight structures from dissimilar sheet materials. Accurate prediction of the fatigue life of clinched joints is essential for ensuring structural safety and minimizing development costs. However, full 3D fatigue simulations over millions of cycles are computationally intensive due to the complexity of contact mechanics. This study introduces a 2D numerical model that circumvents direct contact modeling by applying a slip condition at the sheet interface, significantly reducing computational demands. A micro‐slip friction model is used to represent the mechanical interface behavior, while a two‐scale damage model captures the fatigue damage evolution. The model is validated against experimental data and used to investigate the influence of friction coefficient and tangential contact stiffness on fatigue life, highlighting its efficiency and predictive capability.}}, author = {{Chen, Chin and Hofmann, Martin and Wallmersperger, Thomas}}, issn = {{1617-7061}}, journal = {{PAMM}}, number = {{1}}, publisher = {{Wiley}}, title = {{{A 2D Approach to Predict the High‐Cycle Fatigue Life of Clinched Joints}}}, doi = {{10.1002/pamm.70035}}, volume = {{26}}, year = {{2026}}, } @article{64250, abstract = {{Abstract Salt-spray testing is widely used in the automotive and materials industries to assess the corrosion resistance of protective coatings, where uniform corrosion is a key indicator of material performance. This work presents a numerical uniform corrosion model that predicts the corrosion rate of hot-dip zinc in salt-spray environments by incorporating electrochemical reactions, mass transport via the Nernst–Planck equation, and ionic-strength effects through the Brønsted–Bjerrum relation. The model is calibrated using immersion-test data and extended to account for electrolyte layer growth, droplet deposition, and periodic run-off in salt-spray environments. The calibration establishes a relationship between the porosity of the zinc oxide layer and the rate constant of zinc oxide precipitation. The validated model reproduces the transition from activation- to diffusion-controlled corrosion and captures the experimentally observed corrosion kinetics with an error margin of 20% when electrolyte renewal is included. The results highlight the decisive role of electrolyte dynamics in salt-spray environments and provide a foundation for extending the framework to more complex cyclic corrosion tests.}}, author = {{Chen, Chin and Hofmann, Martin and Wallmersperger, Thomas}}, issn = {{2397-2106}}, journal = {{npj Materials Degradation}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Modeling the uniform corrosion behavior of zinc in salt spray testing}}}, doi = {{10.1038/s41529-026-00749-0}}, year = {{2026}}, } @article{61161, abstract = {{Abstract The effects of corrosion on clinched joints are not completely understood yet. Recent research indicates that galvanic corrosion can actually enhance the fatigue life of clinched joints. It is then of significant interest to investigate the effects of another corrosion phenomenon, pitting corrosion, on the fatigue behavior of clinched joints. Pitting corrosion occurs in passive metals and can lead to stress concentrations. In the present study, the effects of pitting corrosion are investigated by using Lemaitre’s two-scale fatigue model with a 2D geometry of clinched joints. A slip condition is applied as a boundary condition to simplify the clinched joint model and reduce the computational cost of solving the contact mechanics problem. Additionally, a method to determine the damage strength and the damage exponent used in the two-scale damage model is introduced. Numerical simulations reveal that pitting corrosion reduces the fatigue life of clinched joints, particularly when it occurs on the internal surface in the neck area.}}, author = {{Chen, Chin and Harzheim, Sven and Hofmann, Martin and Wallmersperger, Thomas}}, issn = {{0001-5970}}, journal = {{Acta Mechanica}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Numerical investigation of the effects of pitting corrosion on high-cycle fatigue of clinched joints}}}, doi = {{10.1007/s00707-025-04234-8}}, year = {{2025}}, } @article{61411, abstract = {{Abstract The effect of corrosion on mechanically joined components is not well understood. While recent research shows that a brief exposure of clinched specimens to a salt spray environment improves the specimens’ fatigue life, other research shows a decrease in load bearing capabilities with increasing corrosion times. These studies primarily focus on galvanic corrosion. It is not entirely clear how other corrosion phenomena, such as pitting corrosion, affect the fatigue life of clinched joints. In this work, a numerical model is used, which is able to simulate corrosion pit growth in EN AW-6014. The experimental polarization data of EN AW-6014 are used directly in the calculation of the interface kinetics parameter of the model.}}, author = {{Harzheim, Sven and Chen, Chin and Hollmer, Katharina and Hofmann, Martin and Zimmermann, Martina and Wallmersperger, Thomas}}, issn = {{0001-5970}}, journal = {{Acta Mechanica}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Numerical investigation of pitting corrosion in clinched joints}}}, doi = {{10.1007/s00707-025-04248-2}}, year = {{2025}}, } @article{61822, abstract = {{Abstract The effect of corrosion on mechanically joined components is not well understood. While recent research shows that a brief exposure of clinched specimens to a salt spray environment improves the specimens’ fatigue life, other research shows a decrease in load bearing capabilities with increasing corrosion times. These studies primarily focus on galvanic corrosion. It is not entirely clear how other corrosion phenomena, such as pitting corrosion, affect the fatigue life of clinched joints. In this work, a numerical model is used, which is able to simulate corrosion pit growth in EN AW-6014. The experimental polarization data of EN AW-6014 are used directly in the calculation of the interface kinetics parameter of the model.}}, author = {{Harzheim, Sven and Chen, Chin and Hollmer, Katharina and Hofmann, Martin and Zimmermann, Martina and Wallmersperger, Thomas}}, issn = {{0001-5970}}, journal = {{Acta Mechanica}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Numerical investigation of pitting corrosion in clinched joints}}}, doi = {{10.1007/s00707-025-04248-2}}, year = {{2025}}, } @article{61412, abstract = {{AbstractMechanical clinching is a frequently used joining method for technical components. These joints are usually weak spots. Here, corrosion and fatigue are decisive influencing factors for the assessment of the service life of such joints. Corrosion generally leads to material deterioration and thus to premature failure of the joints. Under certain circumstances, however, corrosion can lead to an increased fatigue life. While this effect has not yet been fully understood, the present work provides a possible explanation and a modeling approach to predict the fatigue life of precorroded clinched joints. The increased fatigue life is observed when the clinched components are briefly (up to 3 weeks) exposed to a salt spray environment. During this time, a small layer of corrosion products protrudes from the metal surface and fills the gaps between the joined sheets. Due to the increased contact area, the mechanical stress in the joint decreases, resulting in an improved fatigue performance. Although there are a variety of corrosion phenomena, for example, pitting, intergranular, and transgranular corrosion as well as galvanic corrosion, experimental studies indicate that galvanic corrosion is the main contributor of this effect. In the present work, a coupled electro‐chemo‐mechanical corrosion model is presented and applied to two test cases. Case I: corrosion products growth, and Case II: corrosion products growth and mechanical loading.}}, author = {{Harzheim, Sven and Chen, Chin and Hofmann, Martin and Wallmersperger, Thomas}}, issn = {{1617-7061}}, journal = {{PAMM}}, number = {{4}}, publisher = {{Wiley}}, title = {{{Coupled chemo‐electro‐mechanical model for galvanic corrosion in clinched components}}}, doi = {{10.1002/pamm.202400028}}, volume = {{24}}, year = {{2024}}, } @article{34253, abstract = {{Lightweight construction has increasingly become the focus of scientific research in recent years, not least due to the constantly increasing fuel price, which is a key factor in the economic viability of many companies. In this respect, the use of hybrid structures, made of dissimilar materials offers many advantages. However, such hybrid structures often have undesirable side effects. For example, brittle intermetallic phases are formed when aluminum and steel are welded. Clinching as a mechanical joining process does not produce such intermetallic phases since the connection is realized through form and force closure. In this process, a punch passes through two or more sheets and forms them into a permanent joint in a die. In the present work, the corrosion phenomena of an aluminum-steel clinched joint have been investigated by both experiments and numerical simulations in order to explain the superior fatigue behavior of pre-corroded joints. Therefore, the clinched joints have been corroded by a three-week salt-spray test. In addition, the electric potential and the von Mises stress are calculated under the assumption of a static loading. The results of both experiments and numerical simulations can explain the improvement in the fatigue behavior of the corroded specimens. This phenomenon can be attributed to the accumulation of corrosion products in small gaps between the joined metal sheets.}}, author = {{Harzheim, Sven and Ewenz, Lars and Zimmermann, Martina and Wallmersperger, Thomas}}, issn = {{2666-3309}}, journal = {{Journal of Advanced Joining Processes}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}}, publisher = {{Elsevier BV}}, title = {{{Corrosion Phenomena and Fatigue Behavior of Clinched Joints: Numerical and Experimental Investigations}}}, doi = {{10.1016/j.jajp.2022.100130}}, volume = {{6}}, year = {{2022}}, } @inbook{34209, abstract = {{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 = {{Shi, Yuhao and Harzheim, Sven and Hofmann, Martin and Wallmersperger, Thomas}}, booktitle = {{Material Modeling and Structural Mechanics}}, isbn = {{9783030976743}}, issn = {{1869-8433}}, keywords = {{Hydrogen embrittlement, Fatigue, Continuum damage mechanics, Numerical simulation, Multi-field problem}}, publisher = {{Springer International Publishing}}, title = {{{A Damage Model for Corrosion Fatigue Due to Hydrogen Embrittlement}}}, doi = {{10.1007/978-3-030-97675-0_9}}, year = {{2022}}, } @article{34257, abstract = {{Galvanic corrosion is a destructive process between dissimilar metals. The present paper presents a constructed numerical test case to simulate galvanic corrosion of two dissimilar metals. This test case is used to study the accuracy of different implementations to track the dissolving anode boundary. One technique is to numerically simulate a mesh displacement based on the prescribed displacement at the anode boundary. The second method is to adjust only the boundary elements. Re-meshing after a certain number of time steps is applied to both implementations. They produce similar results for an electrical and electrochemical field problem. This work shows that mesh smoothing does not result in higher accuracy when modeling a moving anode front. Adjusting only the boundary elements is sufficient when frequent re-meshing is used.}}, author = {{Harzheim, Sven and Hofmann, Martin and Wallmersperger, Thomas}}, issn = {{0001-5970}}, journal = {{Acta Mechanica}}, keywords = {{Mechanical Engineering, Computational Mechanics}}, number = {{11}}, pages = {{4427--4439}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Comparison of two mesh-moving techniques for finite element simulations of galvanic corrosion}}}, doi = {{10.1007/s00707-022-03326-z}}, volume = {{233}}, year = {{2022}}, } @article{34261, abstract = {{Mechanical clinching is used to create lightweight hybrid structures. In order to estimate the service life of clinched components, its fatigue properties need to be known under different mechanical loading conditions. In addition to fatigue, corrosion is another factor that affects the fatigue life of clinched joints. In the literature, many corrosion and high-cycle fatigue damage models exist. However, little is known about how both phenomena interact in clinched joints. In this article, the influence of galvanic corrosion on clinched EN AW-6014/HCT590X + Z sheets on the fatigue life is investigated by means of numerical simulations and experimental results. An accurate prediction of the Wöhler lines of non-corroded and pre-corroded clinched specimens is shown.}}, author = {{Harzheim, Sven and Hofmann, Martin and Wallmersperger, Thomas}}, issn = {{1537-6494}}, journal = {{Mechanics of Advanced Materials and Structures}}, keywords = {{Mechanical Engineering, Mechanics of Materials, General Materials Science, General Mathematics, Civil and Structural Engineering}}, pages = {{1--6}}, publisher = {{Informa UK Limited}}, title = {{{Numerical fatigue life prediction of corroded and non-corroded clinched joints}}}, doi = {{10.1080/15376494.2022.2140233}}, year = {{2022}}, } @article{34070, author = {{Schramm, Britta and Harzheim, Sven and Weiß, Deborah and Joy, Tintu David and Hofmann, Martin and Mergheim, Julia and Wallmersperger, Thomas}}, issn = {{2666-3309}}, journal = {{Journal of Advanced Joining Processes}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}}, publisher = {{Elsevier BV}}, title = {{{A Review on the Modeling of the Clinching Process Chain - Part III: Operational Phase}}}, doi = {{10.1016/j.jajp.2022.100135}}, year = {{2022}}, } @article{34069, author = {{Schramm, Britta and Martin, Sven and Steinfelder, Christian and Bielak, Christian Roman and Brosius, Alexander and Meschut, Gerson and Tröster, Thomas and Wallmersperger, Thomas and Mergheim, Julia}}, issn = {{2666-3309}}, journal = {{Journal of Advanced Joining Processes}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}}, publisher = {{Elsevier BV}}, title = {{{A Review on the Modeling of the Clinching Process Chain - Part I: Design Phase}}}, doi = {{10.1016/j.jajp.2022.100133}}, volume = {{6}}, year = {{2022}}, } @article{34068, author = {{Schramm, Britta and Friedlein, Johannes and Gröger, Benjamin and Bielak, Christian Roman and Bobbert, Mathias and Gude, Maik and Meschut, Gerson and Wallmersperger, Thomas and Mergheim, Julia}}, issn = {{2666-3309}}, journal = {{Journal of Advanced Joining Processes}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Engineering (miscellaneous), Chemical Engineering (miscellaneous)}}, publisher = {{Elsevier BV}}, title = {{{A Review on the Modeling of the Clinching Process Chain - Part II: Joining Process}}}, doi = {{10.1016/j.jajp.2022.100134}}, year = {{2022}}, } @article{30664, abstract = {{Corrosion is a major cause for the failure of metallic components in various branches of the industry. Depending on the corrosion severity, the time until failure of the component varies. On the contrary, a study has shown that certain riveted metal joints, exposed to a short period of mechanical loading and corrosion, have greater fatigue limits. This study gives rise to the question how different corrosion exposure times affect joint metallic components. In the present research, a theoretical approach is developed in order to evaluate the influence of galvanic corrosion on joint integrity of clinched metal joints. At first, the framework for modeling galvanic corrosion is introduced. Furthermore, a simulative investigation of a clinching point is carried out based on the assumption that corrosion leads to a reduction of the contact area which leads to a local increase in contact pressure. For this purpose, the stiffness values of individual elements in a finite element model are reduced locally in the contact area of the undercut and the contact stress along a path is evaluated. Summarizing, a modeling approach is introduced to investigate corrosion effects on load-bearing behavior of clinched joints. }}, author = {{Harzheim, S. and Steinfelder, C. and Wallmersperger, T. and Brosius, A.}}, journal = {{Key Engineering Materials}}, pages = {{97--104}}, title = {{{A First Approach for the Treatment of Galvanic Corrosion and of Load-Bearing Capacity of Clinched Joints}}}, doi = {{10.4028/www.scientific.net/kem.883.97}}, volume = {{883}}, year = {{2021}}, } @article{30720, abstract = {{Predicting the durability of components under mechanical loading combined with environmental conditions leading to corrosion is one of the most challenging tasks in mechanical engineering. Precise predictions are neccesary for lightweight design in transportation due to environmental protection. During corrosion often hydrogen is produced by electrochemical reactions. Hydrogen embrittlement is one of the most feared damage mechanisms for metal constructions leading to early and unexpected failure. Until now predictions are mostly done through costly experiments. In the present research, a first simple simulation model based on the fundamentals of electrochemistry and continuum damage mechanics is developed to couple the damage induced by the mechanical stress with the hydrogen embrittlement. Results of the durability are presented for the case of uniaxial cyclic loading for varying testing frequency.}}, author = {{Hofmann, M. and Shi, Y. and Wallmersperger, T.}}, journal = {{PAMM}}, title = {{{A first Model of Fatigue Corrosion of a Metal through Hydrogen Embrittlement}}}, doi = {{10.1002/pamm.202000122}}, volume = {{20}}, year = {{2021}}, }