@article{VuStaat2004,
  author    = {Vu, Duc-Khoi and Staat, Manfred},
  title     = {An algorithm for shakedown analysis of structure with temperature dependent yield stress},
  year      = {2004},
  abstract  = {This work is an attempt to answer the question: How to use convex programming in shakedown analysis of structures made of materials with temperature-dependent properties. Based on recently established shakedown theorems and formulations, a dual relationship between upper and lower bounds of the shakedown limit load is found, an algorithmfor shakedown analysis is proposed. While the original problem is neither convex nor concave, the algorithm presented here has the advantage of employing convex programming tools.},
  subject      = {Einspielen <Werkstoff>},
  language  = {en}
}
@article{CiritsisHorbachStaatetal.2018,
  author    = {Ciritsis, Alexander and Horbach, Andreas and Staat, Manfred and Kuhl, Christiane K. and Kraemer, Nils Andreas},
  title     = {Porosity and tissue integration of elastic mesh implants evaluated in vitro and in vivo},
  series = {Journal of Biomedical Materials Research: Part B: Applied Biomaterials},
  volume    = {106},
  journal   = {Journal of Biomedical Materials Research: Part B: Applied Biomaterials},
  number    = {2},
  publisher = {Wiley},
  address   = {New York, NY},
  issn      = {1552-4981},
  doi       = {10.1002/jbm.b.33877},
  pages     = {827 -- 833},
  year      = {2018},
  abstract  = {Purpose In vivo, a loss of mesh porosity triggers scar tissue formation and restricts functionality. The purpose of this study was to evaluate the properties and configuration changes as mesh deformation and mesh shrinkage of a soft mesh implant compared with a conventional stiff mesh implant in vitro and in a porcine model. Material and Methods Tensile tests and digital image correlation were used to determine the textile porosity for both mesh types in vitro. A group of three pigs each were treated with magnetic resonance imaging (MRI) visible conventional stiff polyvinylidene fluoride meshes (PVDF) or with soft thermoplastic polyurethane meshes (TPU) (FEG Textiltechnik mbH, Aachen, Germany), respectively. MRI was performed with a pneumoperitoneum at a pressure of 0 and 15 mmHg, which resulted in bulging of the abdomen. The mesh-induced signal voids were semiautomatically segmented and the mesh areas were determined. With the deformations assessed in both mesh types at both pressure conditions, the porosity change of the meshes after 8 weeks of ingrowth was calculated as an indicator of preserved elastic properties. The explanted specimens were examined histologically for the maturity of the scar (collagen I/III ratio). Results In TPU, the in vitro porosity increased constantly, in PVDF, a loss of porosity was observed under mild stresses. In vivo, the mean mesh areas of TPU were 206.8 cm2 (± 5.7 cm2) at 0 mmHg pneumoperitoneum and 274.6 cm2 (± 5.2 cm2) at 15 mmHg; for PVDF the mean areas were 205.5 cm2 (± 8.8 cm2) and 221.5 cm2 (± 11.8 cm2), respectively. The pneumoperitoneum-induced pressure increase resulted in a calculated porosity increase of 8.4\% for TPU and of 1.2\% for PVDF. The mean collagen I/III ratio was 8.7 (± 0.5) for TPU and 4.7 (± 0.7) for PVDF. Conclusion The elastic properties of TPU mesh implants result in improved tissue integration compared to conventional PVDF meshes, and they adapt more efficiently to the abdominal wall. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 827-833, 2018.},
  language  = {en}
}
@misc{HacklWegmannKahmannetal.2017,
  author    = {Hackl, Michael and Wegmann, Kilian and Kahmann, Stephanie Lucina and Heinze, Nicolai and Staat, Manfred and Neiss, Wolfram F. and Scaal, Martin and M{\"u}ller, Lars P.},
  title     = {Reply to the letter to the editor: shortening osteotomy of the proximal radius},
  series = {Knee Surgery, Sports Traumatology, Arthroscopy},
  volume    = {25},
  journal   = {Knee Surgery, Sports Traumatology, Arthroscopy},
  number    = {10},
  doi       = {10.1007/s00167-017-4666-8},
  pages     = {3328 -- 3329},
  year      = {2017},
  language  = {en}
}
@inproceedings{TranMatthiesStavroulakisetal.2018,
  author    = {Tran, Ngoc Trinh and Matthies, Hermann G. and Stavroulakis, Georgios Eleftherios and Staat, Manfred},
  title     = {Direct plastic structural design by chance constrained programming},
  series = {6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK},
  booktitle = {6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK},
  pages     = {12 Seiten},
  year      = {2018},
  abstract  = {We propose a stochastic programming method to analyse limit and shakedown of structures under random strength with lognormal distribution. In this investigation a dual chance constrained programming algorithm is developed to calculate simultaneously both the upper and lower bounds of the plastic collapse limit or the shakedown limit. The edge-based smoothed finite element method (ES-FEM) using three-node linear triangular elements is used.},
  language  = {en}
}
@article{StaatHeitzerLangetal.2005,
  author    = {Staat, Manfred and Heitzer, M. and Lang, H. and Wirtz, K.},
  title     = {Direct Finite Element Route for Design-by-Analysis of Pressure Components},
  series = {International Journal of Pressure Vessels and Piping. 82 (2005), H. 1},
  journal   = {International Journal of Pressure Vessels and Piping. 82 (2005), H. 1},
  isbn      = {0308-0161},
  pages     = {61 -- 67},
  year      = {2005},
  language  = {en}
}
@inproceedings{DuongNguyenStaat2012,
  author    = {Duong, Minh Tuan and Nguyen, Nhu Huynh and Staat, Manfred},
  title     = {Numerical stability enhancement of modeling hyperelastic materials},
  series = {Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012)},
  booktitle = {Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012)},
  editor    = {Eberhardsteiner, J.},
  year      = {2012},
  language  = {en}
}
@article{HacklAndermahrStaatetal.2017,
  author    = {Hackl, M. and Andermahr, J. and Staat, Manfred and Bremer, I. and Borggrefe, J. and Prescher, A. and M{\"u}ller, L. P. and Wegmann, K.},
  title     = {Suture button reconstruction of the central band of the interosseous membrane in Essex-Lopresti lesions: a comparative biomechanical investigation},
  series = {The Journal of Hand Surgery (European Volume)},
  volume    = {42},
  journal   = {The Journal of Hand Surgery (European Volume)},
  number    = {4},
  publisher = {Sage},
  address   = {London},
  issn      = {2043-6289 (Online)},
  doi       = {10.1177/1753193416665943},
  pages     = {370 -- 376},
  year      = {2017},
  language  = {en}
}
@article{TopcuMadabhushiStaat2022,
  author    = {Top{\c{c}}u, Murat and Madabhushi, Gopal S.P. and Staat, Manfred},
  title     = {A generalized shear-lag theory for elastic stress transfer between matrix and fibres having a variable radius},
  series = {International Journal of Solids and Structures},
  volume    = {239-240},
  journal   = {International Journal of Solids and Structures},
  number    = {Art. No. 111464},
  publisher = {Elsevier},
  address   = {New York, NY},
  issn      = {0020-7683},
  doi       = {10.1016/j.ijsolstr.2022.111464},
  year      = {2022},
  abstract  = {A generalized shear-lag theory for fibres with variable radius is developed to analyse elastic fibre/matrix stress transfer. The theory accounts for the reinforcement of biological composites, such as soft tissue and bone tissue, as well as for the reinforcement of technical composite materials, such as fibre-reinforced polymers (FRP). The original shear-lag theory proposed by Cox in 1952 is generalized for fibres with variable radius and with symmetric and asymmetric ends. Analytical solutions are derived for the distribution of axial and interfacial shear stress in cylindrical and elliptical fibres, as well as conical and paraboloidal fibres with asymmetric ends. Additionally, the distribution of axial and interfacial shear stress for conical and paraboloidal fibres with symmetric ends are numerically predicted. The results are compared with solutions from axisymmetric finite element models. A parameter study is performed, to investigate the suitability of alternative fibre geometries for use in FRP.},
  language  = {en}
}
@article{BhattaraiHorbachStaatetal.2022,
  author    = {Bhattarai, Aroj and Horbach, Andreas and Staat, Manfred and Kowalczyk, Wojciech and Tran, Thanh Ngoc},
  title     = {Virgin passive colon biomechanics and a literature review of active contraction constitutive models},
  series = {Biomechanics},
  volume    = {2},
  journal   = {Biomechanics},
  number    = {2},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2673-7078},
  doi       = {10.3390/biomechanics2020013},
  pages     = {138 -- 157},
  year      = {2022},
  abstract  = {The objective of this paper is to present our findings on the biomechanical aspects of the virgin passive anisotropic hyperelasticity of the porcine colon based on equibiaxial tensile experiments. Firstly, the characterization of the intestine tissues is discussed for a nearly incompressible hyperelastic fiber-reinforced Holzapfel-Gasser-Ogden constitutive model in virgin passive loading conditions. The stability of the evaluated material parameters is checked for the polyconvexity of the adopted strain energy function using positive eigenvalue constraints of the Hessian matrix with MATLAB. The constitutive material description of the intestine with two collagen fibers in the submucosal and muscular layer each has been implemented in the FORTRAN platform of the commercial finite element software LS-DYNA, and two equibiaxial tensile simulations are presented to validate the results with the optical strain images obtained from the experiments. Furthermore, this paper also reviews the existing models of the active smooth muscle cells, but these models have not been computationally studied here. The review part shows that the constitutive models originally developed for the active contraction of skeletal muscle based on Hill's three-element model, Murphy's four-state cross-bridge chemical kinetic model and Huxley's sliding-filament hypothesis, which are mainly used for arteries, are appropriate for numerical contraction numerical analysis of the large intestine.},
  language  = {en}
}
@article{AbelKahmannMellonetal.2020,
  author    = {Abel, Alexander and Kahmann, Stephanie Lucina and Mellon, Stephen and Staat, Manfred and Jung, Alexander},
  title     = {An open-source tool for the validation of finite element models using three-dimensional full-field measurements},
  series = {Medical Engineering \& Physics},
  volume    = {77},
  journal   = {Medical Engineering \& Physics},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1350-4533},
  doi       = {10.1016/j.medengphy.2019.10.015},
  pages     = {125 -- 129},
  year      = {2020},
  abstract  = {Three-dimensional (3D) full-field measurements provide a comprehensive and accurate validation of finite element (FE) models. For the validation, the result of the model and measurements are compared based on two respective point-sets and this requires the point-sets to be registered in one coordinate system. Point-set registration is a non-convex optimization problem that has widely been solved by the ordinary iterative closest point algorithm. However, this approach necessitates a good initialization without which it easily returns a local optimum, i.e. an erroneous registration. The globally optimal iterative closest point (Go-ICP) algorithm has overcome this drawback and forms the basis for the presented open-source tool that can be used for the validation of FE models using 3D full-field measurements. The capability of the tool is demonstrated using an application example from the field of biomechanics. Methodological problems that arise in real-world data and the respective implemented solution approaches are discussed.},
  language  = {en}
}
@inproceedings{JungFrotscherStaat2018,
  author    = {Jung, Alexander and Frotscher, Ralf and Staat, Manfred},
  title     = {Electromechanical model of hiPSC-derived ventricular cardiomyocytes cocultured with fibroblasts},
  series = {6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK},
  booktitle = {6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK},
  pages     = {11 Seiten},
  year      = {2018},
  abstract  = {The CellDrum provides an experimental setup to study the mechanical effects of fibroblasts co-cultured with hiPSC-derived ventricular cardiomyocytes. Multi-scale computational models based on the Finite Element Method are developed. Coupled electrical cardiomyocyte-fibroblast models (cell level) are embedded into reaction-diffusion equations (tissue level) which compute the propagation of the action potential in the cardiac tissue. Electromechanical coupling is realised by an excitation-contraction model (cell level) and the active stress arising during contraction is added to the passive stress in the force balance, which determines the tissue displacement (tissue level). Tissue parameters in the model can be identified experimentally to the specific sample.},
  language  = {en}
}
@inproceedings{KahmannUschokWegmannetal.2018,
  author    = {Kahmann, Stephanie Lucina and Uschok, Stephan and Wegmann, Kilian and M{\"u}ller, Lars-P. and Staat, Manfred},
  title     = {Biomechanical multibody model with refined kinematics of the elbow},
  series = {6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK},
  booktitle = {6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK},
  pages     = {11 Seiten},
  year      = {2018},
  abstract  = {The overall objective of this study is to develop a new external fixator, which closely maps the native kinematics of the elbow to decrease the joint force resulting in reduced rehabilitation time and pain. An experimental setup was designed to determine the native kinematics of the elbow during flexion of cadaveric arms. As a preliminary study, data from literature was used to modify a published biomechanical model for the calculation of the joint and muscle forces. They were compared to the original model and the effect of the kinematic refinement was evaluated. Furthermore, the obtained muscle forces were determined in order to apply them in the experimental setup. The joint forces in the modified model differed slightly from the forces in the original model. The muscle force curves changed particularly for small flexion angles but their magnitude for larger angles was consistent.},
  language  = {en}
}
@article{AndingTabazaStaatetal.2013,
  author    = {Anding, Ralf and Tabaza, Ruth and Staat, Manfred and Trenz, Eva and Lohmann, Philipp and Klinge, Uwe and Kirschner-Hermanns, Ruth},
  title     = {Introducing a method of in vitro testing of different anchoring systems used for female incontinence and prolapse surgery},
  series = {BioMed research international},
  volume    = {Vol. 2013},
  journal   = {BioMed research international},
  issn      = {1110-7251 (E-Journal); 2314-6141 (E-Journal); 1110-7243 (Print); 2314-6133 (Print)},
  pages     = {Article ID 401417},
  year      = {2013},
  language  = {en}
}
@misc{StaatBarry2006,
  author    = {Staat, Manfred and Barry, Steve},
  title     = {Continuum Mechanics with an Introduction to the Finite Element Method / Steve Barry; Manfred Staat. With extensions by Manfred Staat.},
  year      = {2006},
  abstract  = {Contents: 1 Introduction 2 One Dimensional Continuum Mechanics 3 Tensors 4 Three Dimensional Stress and Strain 5 Conservation Laws 6 Contiunuum Modelling 7 Plain Problems 8 Questions 9 Reference Information},
  subject      = {Technische Mechanik},
  language  = {en}
}
@article{HacklLeschingerStaatetal.2016,
  author    = {Hackl, Michael and Leschinger, T. and Staat, Manfred and M{\"u}ller, Lars-Peter and Wegmann, Kilian},
  title     = {Reconstruction of the interosseous membrane in the Essex Lopresti lesion — a biomechanical evaluation},
  series = {Knee surgery, sports traumatology, arthroscopy},
  volume    = {Volume 24},
  journal   = {Knee surgery, sports traumatology, arthroscopy},
  number    = {Supplement 1},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {0942-2056},
  doi       = {10.1007/s00167-016-4080-7},
  pages     = {130 -- 131},
  year      = {2016},
  abstract  = {Surgical reconstruction of the interosseous membrane (IOM) could restore longitudinal forearm stability to avoid persisting disability due to capituloradial and ulnocarpal impingement in Essex Lopresti lesions. This biomechanical study aimed to assess longitudinal forearm stability of intact specimens, after sectioning of the IOM and after reconstruction with a TightRope construct using either a single or double bundle technique.},
  language  = {en}
}
@inproceedings{BhattaraiFrotscherStaat2015,
  author    = {Bhattarai, Aroj and Frotscher, Ralf and Staat, Manfred},
  title     = {Biomechanical study of the female pelvic floor dysfunction using the finite element method},
  series = {Conference proceedings of the YIC GACM 2015 : 3rd ECCOMAS Young Investigators Conference and 6th GACM Colloquium on Computational Mechanics , Aachen , Germany, 20.07.2015 - 23.07.2015 / ed.: Stefanie Elgeti ; Jaan-Willem Simon},
  booktitle = {Conference proceedings of the YIC GACM 2015 : 3rd ECCOMAS Young Investigators Conference and 6th GACM Colloquium on Computational Mechanics , Aachen , Germany, 20.07.2015 - 23.07.2015 / ed.: Stefanie Elgeti ; Jaan-Willem Simon},
  publisher = {RWTH Aachen University},
  address   = {Aachen},
  organization    = {ECCOMAS Young Investigators Conference <3, 2015, Aachen>},
  pages     = {1 -- 4},
  year      = {2015},
  language  = {en}
}
@misc{JungMuellerStaat2021,
  author    = {Jung, Alexander and M{\"u}ller, Wolfram and Staat, Manfred},
  title     = {Corrigendum to "Wind and fairness in ski jumping: A computer modelling analysis" [J. Biomech. 75 (2018) 147-153]},
  series = {Journal of Biomechanics},
  volume    = {128},
  journal   = {Journal of Biomechanics},
  number    = {Article number: 110690},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0021-9290},
  doi       = {10.1016/j.jbiomech.2021.110690},
  pages     = {1 Seite},
  year      = {2021},
  language  = {en}
}
@incollection{BhattaraiFrotscherStaat2018,
  author    = {Bhattarai, Aroj and Frotscher, Ralf and Staat, Manfred},
  title     = {Computational Analysis of Pelvic Floor Dysfunction},
  series = {Women's Health and Biomechanics},
  booktitle = {Women's Health and Biomechanics},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-319-71574-2},
  doi       = {10.1007/978-3-319-71574-2_17},
  pages     = {217 -- 230},
  year      = {2018},
  abstract  = {Pelvic floor dysfunction (PFD) is characterized by the failure of the levator ani (LA) muscle to maintain the pelvic hiatus, resulting in the descent of the pelvic organs below the pubococcygeal line. This chapter adopts the modified Humphrey material model to consider the effect of the muscle fiber on passive stretching of the LA muscle. The deformation of the LA muscle subjected to intra-abdominal pressure during Valsalva maneuver is compared with the magnetic resonance imaging (MRI) examination of a nulliparous female. Numerical result shows that the fiber-based Humphrey model simulates the muscle behavior better than isotropic constitutive models. Greater posterior movement of the LA muscle widens the levator hiatus due to lack of support from the anococcygeal ligament and the perineal structure as a consequence of birth-related injury and aging. Old and multiparous females with uncontrolled urogenital and rectal hiatus tend to develop PFDs such as prolapse and incontinence.},
  language  = {en}
}
@article{WegmannHacklStaatetal.2016,
  author    = {Wegmann, Kilian and Hackl, Michael and Staat, Manfred and Mayer, Katharina and M{\"u}ller, Lars-Peter},
  title     = {Double plate osteosynthesis of proximal ulna fractures: biomechanical and clinical results},
  series = {Knee surgery, sports traumatology, arthroscopy},
  volume    = {Volume 24},
  journal   = {Knee surgery, sports traumatology, arthroscopy},
  number    = {Supplement 1},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {0942-2056},
  doi       = {10.1007/s00167-016-4079-0},
  pages     = {58 -- 59},
  year      = {2016},
  abstract  = {While plate fixation of proximal ulna fractures might lead to superior clinical results compared to tension band wiring, regular plates represent an established risk factor for wound complications. The olecranon double plates (Medartis, Basel, CH) might decrease complications related to the osteosynthesis because of their low profile and better anatomical fit. This study aimed to evaluate the biomechanical performance and clinical results of the olecranon double plates.},
  language  = {en}
}
@article{JungStaatMueller2013,
  author    = {Jung, Alexander and Staat, Manfred and M{\"u}ller, Wolfram},
  title     = {Flight style optimization in ski jumping on normal, large, and ski flying hills},
  series = {Journal of biomechanics},
  volume    = {Vol. 47},
  journal   = {Journal of biomechanics},
  number    = {Iss. 3},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1873-2380 (E-Journal); 0021-9290 (Print)},
  pages     = {716 -- 722},
  year      = {2013},
  language  = {en}
}