[{"publisher":"Elsevier BV","date_created":"2025-01-31T17:04:12Z","title":"Modelling of stress-state-dependent ductile damage with gradient-enhancement exemplified for clinch joining","year":"2025","keyword":["Finite plasticity","Ductile damage","Gradient-enhancement","Stress-state dependency","Failure"],"language":[{"iso":"eng"}],"publication":"Journal of the Mechanics and Physics of Solids","abstract":[{"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.","lang":"eng"}],"date_updated":"2025-01-31T17:06:22Z","author":[{"last_name":"Friedlein","full_name":"Friedlein, Johannes","first_name":"Johannes"},{"first_name":"Julia","last_name":"Mergheim","full_name":"Mergheim, Julia"},{"first_name":"Paul","last_name":"Steinmann","full_name":"Steinmann, Paul"}],"volume":196,"doi":"10.1016/j.jmps.2025.106026","publication_status":"published","publication_identifier":{"issn":["0022-5096"]},"citation":{"ama":"Friedlein J, Mergheim J, Steinmann P. Modelling of stress-state-dependent ductile damage with gradient-enhancement exemplified for clinch joining. <i>Journal of the Mechanics and Physics of Solids</i>. 2025;196. doi:<a href=\"https://doi.org/10.1016/j.jmps.2025.106026\">10.1016/j.jmps.2025.106026</a>","chicago":"Friedlein, Johannes, Julia Mergheim, and Paul Steinmann. “Modelling of Stress-State-Dependent Ductile Damage with Gradient-Enhancement Exemplified for Clinch Joining.” <i>Journal of the Mechanics and Physics of Solids</i> 196 (2025). <a href=\"https://doi.org/10.1016/j.jmps.2025.106026\">https://doi.org/10.1016/j.jmps.2025.106026</a>.","ieee":"J. Friedlein, J. Mergheim, and P. Steinmann, “Modelling of stress-state-dependent ductile damage with gradient-enhancement exemplified for clinch joining,” <i>Journal of the Mechanics and Physics of Solids</i>, vol. 196, Art. no. 106026, 2025, doi: <a href=\"https://doi.org/10.1016/j.jmps.2025.106026\">10.1016/j.jmps.2025.106026</a>.","apa":"Friedlein, J., Mergheim, J., &#38; Steinmann, P. (2025). Modelling of stress-state-dependent ductile damage with gradient-enhancement exemplified for clinch joining. <i>Journal of the Mechanics and Physics of Solids</i>, <i>196</i>, Article 106026. <a href=\"https://doi.org/10.1016/j.jmps.2025.106026\">https://doi.org/10.1016/j.jmps.2025.106026</a>","bibtex":"@article{Friedlein_Mergheim_Steinmann_2025, title={Modelling of stress-state-dependent ductile damage with gradient-enhancement exemplified for clinch joining}, volume={196}, DOI={<a href=\"https://doi.org/10.1016/j.jmps.2025.106026\">10.1016/j.jmps.2025.106026</a>}, 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} }","short":"J. Friedlein, J. Mergheim, P. Steinmann, Journal of the Mechanics and Physics of Solids 196 (2025).","mla":"Friedlein, Johannes, et al. “Modelling of Stress-State-Dependent Ductile Damage with Gradient-Enhancement Exemplified for Clinch Joining.” <i>Journal of the Mechanics and Physics of Solids</i>, vol. 196, 106026, Elsevier BV, 2025, doi:<a href=\"https://doi.org/10.1016/j.jmps.2025.106026\">10.1016/j.jmps.2025.106026</a>."},"intvolume":"       196","project":[{"grant_number":"418701707","_id":"130","name":"TRR 285: TRR 285:  Methodenentwicklung zur mechanischen Fügbarkeit in wandlungsfähigen Prozessketten"},{"_id":"131","name":"TRR 285 - A: TRR 285 - Project Area A"},{"name":"TRR 285 – A05: TRR 285 - Subproject A05","_id":"139"}],"_id":"58492","user_id":"84990","article_number":"106026","article_type":"original","type":"journal_article","status":"public"},{"article_type":"original","article_number":"104946","keyword":["Finite plasticity","Logarithmic strain space","Ductile damage","Gradient-enhancement","Gradient-plasticity","Gradient-damage","Loss of ellipticity"],"language":[{"iso":"eng"}],"project":[{"name":"TRR 285: TRR 285","_id":"130"},{"name":"TRR 285 - A: TRR 285 - Project Area A","_id":"131"},{"name":"TRR 285 – A05: TRR 285 - Subproject A05","_id":"139"},{"name":"TRR 285:  Methodenentwicklung zur mechanischen Fügbarkeit in wandlungsfähigen Prozessketten","_id":"130"}],"_id":"56097","user_id":"84990","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."}],"status":"public","type":"journal_article","publication":"European Journal of Mechanics - A/Solids","title":"Efficient gradient enhancements for plasticity with ductile damage in the logarithmic strain space","doi":"10.1016/j.euromechsol.2023.104946","publisher":"Elsevier BV","date_updated":"2026-02-24T14:37:05Z","author":[{"first_name":"Johannes","full_name":"Friedlein, Johannes","last_name":"Friedlein"},{"first_name":"Julia","full_name":"Mergheim, Julia","last_name":"Mergheim"},{"last_name":"Steinmann","full_name":"Steinmann, Paul","first_name":"Paul"}],"date_created":"2024-09-10T15:23:49Z","volume":99,"year":"2023","citation":{"apa":"Friedlein, J., Mergheim, J., &#38; Steinmann, P. (2023). Efficient gradient enhancements for plasticity with ductile damage in the logarithmic strain space. <i>European Journal of Mechanics - A/Solids</i>, <i>99</i>, Article 104946. <a href=\"https://doi.org/10.1016/j.euromechsol.2023.104946\">https://doi.org/10.1016/j.euromechsol.2023.104946</a>","ama":"Friedlein J, Mergheim J, Steinmann P. Efficient gradient enhancements for plasticity with ductile damage in the logarithmic strain space. <i>European Journal of Mechanics - A/Solids</i>. 2023;99. doi:<a href=\"https://doi.org/10.1016/j.euromechsol.2023.104946\">10.1016/j.euromechsol.2023.104946</a>","short":"J. Friedlein, J. Mergheim, P. Steinmann, European Journal of Mechanics - A/Solids 99 (2023).","bibtex":"@article{Friedlein_Mergheim_Steinmann_2023, title={Efficient gradient enhancements for plasticity with ductile damage in the logarithmic strain space}, volume={99}, DOI={<a href=\"https://doi.org/10.1016/j.euromechsol.2023.104946\">10.1016/j.euromechsol.2023.104946</a>}, number={104946}, journal={European Journal of Mechanics - A/Solids}, publisher={Elsevier BV}, author={Friedlein, Johannes and Mergheim, Julia and Steinmann, Paul}, year={2023} }","mla":"Friedlein, Johannes, et al. “Efficient Gradient Enhancements for Plasticity with Ductile Damage in the Logarithmic Strain Space.” <i>European Journal of Mechanics - A/Solids</i>, vol. 99, 104946, Elsevier BV, 2023, doi:<a href=\"https://doi.org/10.1016/j.euromechsol.2023.104946\">10.1016/j.euromechsol.2023.104946</a>.","ieee":"J. Friedlein, J. Mergheim, and P. Steinmann, “Efficient gradient enhancements for plasticity with ductile damage in the logarithmic strain space,” <i>European Journal of Mechanics - A/Solids</i>, vol. 99, Art. no. 104946, 2023, doi: <a href=\"https://doi.org/10.1016/j.euromechsol.2023.104946\">10.1016/j.euromechsol.2023.104946</a>.","chicago":"Friedlein, Johannes, Julia Mergheim, and Paul Steinmann. “Efficient Gradient Enhancements for Plasticity with Ductile Damage in the Logarithmic Strain Space.” <i>European Journal of Mechanics - A/Solids</i> 99 (2023). <a href=\"https://doi.org/10.1016/j.euromechsol.2023.104946\">https://doi.org/10.1016/j.euromechsol.2023.104946</a>."},"intvolume":"        99","publication_status":"published","publication_identifier":{"issn":["0997-7538"]}}]