@article{66457,
  abstract     = {{<jats:title>Abstract</jats:title>
                  <jats:p>The service life of fatigue-loaded components that already contain manufacturing‑induced microcracks is primarily governed by the direction and the rate of fatigue-crack growth. When multiple loading components (e.g., tension, compression, shear) act simultaneously but not in temporal synchrony, out‑of‑phase mixed‑mode conditions occur. Such loadings are typical for automotive chassis parts and mechanically joined sheet‑metal assemblies. For optimized design of structural components, the crack kinking angle that occurs under mixed‑mode loading must be predicted as accurately as possible. At present, however, this is still challenging for out‑of‑phase loading conditions. To investigate the associated crack kinking behavior, a novel Compact‑Tension‑Shear‑Mini (CTSM) specimen was developed, enabling controlled generation of plane out-of-phase mixed-mode loading states. Experiments were performed under various combinations of cyclic and static mode I and mode II load components and compared with the analytical predictions of the Out-of-Phase Mixed-Mode (OMM) concept. The measured crack kinking angles showed very good agreement with the predicted values, with mean deviations of only a few degrees, demonstrating the validity and reproducibility of the approach. These findings confirm the applicability of the OMM concept for describing fatigue‑crack propagation under non‑proportional mixed‑mode loading and provide a basis for fatigue‑life assessment of clinched joints and other cyclic multi-axially loaded components.</jats:p>}},
  author       = {{Krome, Sven and Kullmer, Gunter and Weiß, Deborah and Duffe, Tobias and Ostwald, Richard}},
  issn         = {{2731-6564}},
  journal      = {{Discover Mechanical Engineering}},
  number       = {{1}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Experimental determination of kinking angles with out-of-phase mixed-mode loading by means of a novel specimen geometry}}},
  doi          = {{10.1007/s44245-026-00236-5}},
  volume       = {{5}},
  year         = {{2026}},
}

@article{66673,
  abstract     = {{<jats:p>Investigating crack growth in sheet metal originating from clinched joints is a major part of predicting the service life of mechanically joined structures. Clinching allows different materials to be joined together. A key task in this context is to perform crack growth simulations in the vicinity of clinched joints considering different load and environmental conditions. This requires formulaic descriptions of the fatigue crack growth rate curves for the materials used. For this purpose, fatigue crack growth rate curves for different R-ratios and temperatures are determined experimentally. Generally, these fatigue crack growth rate curves can be described very well using a novel two-part exponential approach for the formulaic description of fatigue crack growth rate curves developed at Applied Mechanics of Paderborn University (FAM). In this case, three parameters are sufficient to describe the fatigue crack growth rate curves. For the material HCT590X, which is frequently used in clinched joints, it is shown as an example how the parameters vary with the R-ratio and the temperature. In addition, at high crack growth rates, a significant rise in the fatigue crack growth rate curve sometimes occurs at both low and high temperatures. To account for this feature, the two-part exponential approach can be expanded to include a third part.</jats:p>}},
  author       = {{Kullmer, Gunter and Krome, Sven and Weiß, Deborah and Schramm, Britta and Ostwald, Richard}},
  issn         = {{2075-4701}},
  journal      = {{Metals}},
  number       = {{8}},
  publisher    = {{MDPI AG}},
  title        = {{{Influence of the R-Ratio and the Temperature on the Coefficients of a Novel Exponential Approach for the Formulaic Description of Fatigue Crack Growth Rate Curves}}},
  doi          = {{10.3390/met16080835}},
  volume       = {{16}},
  year         = {{2026}},
}

@article{67066,
  author       = {{Kullmer, Gunter and Krome, Sven and Ostwald, Richard}},
  issn         = {{0013-7944}},
  journal      = {{Engineering Fracture Mechanics}},
  publisher    = {{Elsevier BV}},
  title        = {{{A new approach for the formulaic description of the crack growth rate curve for long cracks in aluminum alloys}}},
  doi          = {{10.1016/j.engfracmech.2026.112568}},
  volume       = {{345}},
  year         = {{2026}},
}

@article{63662,
  abstract     = {{The accurate prediction of crack initiation and propagation is essential for assessing the structural integrity of mechanically joined components and other complex assemblies. To overcome the limitations of existing finite element tools, a modular Python framework has been developed to automate three-dimensional crack growth simulations. The program combines geometric reconstruction, adaptive remeshing, and the numerical evaluation of fracture mechanics parameters within a single, fully automated workflow. The framework builds on open-source components and remains solver-independent, enabling straightforward integration with commercial or research finite element codes. A dedicated sequence of modules performs all required steps, from mesh separation and crack insertion to local submodeling, stress and displacement mapping, and iterative crack-front update, without manual interaction. The methodology was verified using a mini-compact tension (Mini-CT) specimen as a benchmark case. The numerical results demonstrate the accurate reproduction of stress intensity factors and energy release rates while achieving high computational efficiency through localized refinement. The developed approach provides a robust basis for crack growth simulations of geometrically complex or residual stress-affected structures. Its high degree of automation and flexibility makes it particularly suited for analyzing cracks in clinched and riveted joints, supporting the predictive design and durability assessment of joined lightweight structures.}},
  author       = {{Krome, Sven and Duffe, Tobias and Kullmer, Gunter and Schramm, Britta and Ostwald, Richard}},
  issn         = {{2076-3417}},
  journal      = {{Applied Sciences}},
  number       = {{1}},
  publisher    = {{MDPI AG}},
  title        = {{{Validation and Verification of Novel Three-Dimensional Crack Growth Simulation Software GmshCrack3D}}},
  doi          = {{10.3390/app16010384}},
  volume       = {{16}},
  year         = {{2025}},
}

@misc{63764,
  author       = {{Weiß, Deborah and Krome, Sven and Duffe, Tobias and Kullmer, Gunter and Ostwald, Richard}},
  publisher    = {{LibreCat University}},
  title        = {{{Experimentelle Ermittlung von Rissablenkungswinkeln bei außerphasiger Mixed-Mode-Belastung mittels einer neuartigen Probengeometrie}}},
  doi          = {{https://doi.org/10.48447/BR-2025-490}},
  year         = {{2025}},
}

@misc{63667,
  author       = {{Kullmer, G. and Weiss, D. and Krome, Sven and A. Richard, H.}},
  publisher    = {{LibreCat University}},
  title        = {{{Entwicklung einer Einspannvorrichtung für Axialrissproben zur Ermittlung von bruchmechanischen Kennwerten für Rohre}}},
  doi          = {{10.48447/BR-2022-011}},
  year         = {{2022}},
}