@inproceedings{StaatHeitzer1997,
  author    = {Staat, Manfred and Heitzer, Michael},
  title     = {Direkte FEM-Berechnung der Tragf{\"a}higkeit hochbeanspruchter passiver Komponenten},
  year      = {1997},
  abstract  = {Genaue Kenntnis der Spannungen und Verformungen in passiven Komponenten gewinnt man mit detailierten inelastischen FEM Analysen. Die lokale Beanspruchung l{\"a}ßt sich aber nicht direkt mit einer Beanspruchbarkeit im strukturmechanischen Sinne vergleichen. Konzentriert man sich auf die Frage nach der Tragf{\"a}higkeit, dann vereinfacht sich die Analyse. Im Rahmen der Plastizit{\"a}tstheorie berechnen Traglast- und Einspielanalyse die tragbaren Lasten direkt und exakt. In diesem Beitrag wird eine Implementierung der Traglast- und Einspiels{\"a}tze in ein allgemeines FEM Programm vorgestellt, mit der die Tragf{\"a}higkeit passiver Komponenten direkt berechnet wird. Die benutzten Konzepte werden in Bezug auf die {\"u}bliche Strukturanalyse erl{\"a}utert. Beispiele mit lokal hoher Beanspruchung verdeutlichen die Anwendung der FEM basierten Traglast- und Einspielanalysen. Die berechneten Interaktionsdiagramme geben einen guten {\"U}berblick {\"u}ber die m{\"o}glichen Betriebsbereiche passiver Komponenten. Die Traglastanalyse bietet auch einen strukturmechanischen Zugang zur Kollapslast rißbehafteter Komponenten aus hochz{\"a}hem Material.},
  subject      = {Finite-Elemente-Methode},
  language  = {de}
}
@inproceedings{BallmannRaatschenStaat1985,
  author    = {Ballmann, J. and Raatschen, Hans-J{\"u}rgen and Staat, Manfred},
  title     = {High stress intensities in focussing zones of waves},
  doi       = {10.1016/B978-0-444-42520-1.50015-3},
  year      = {1985},
  abstract  = {The propagation of mechanical waves in plates of isotropic elastic material is investigated. After a short introduction to the understanding of focussing of stress waves in a plate with a curved boundary the method of characteristics is applied to a plate of hyperelastic material. Using this method the propagation of acceleration waves is discussed. Based on this a numerical difference scheme is developed for solving initial-boundary-value problems and applied to two examples: propagation of a point disturbance in a homogeneously finitely strained non-linear elastic plate and geometrical focussing in al linear elastic plate.},
  subject      = {Technische Mechanik},
  language  = {en}
}
@article{StaatHeitzer1997,
  author    = {Staat, Manfred and Heitzer, M.},
  title     = {Limit and Shakedown Analysis for Plastic Safety of Complex Structures},
  series = {Transactions of the 14th International Conference on Structural Dynamics in Reactor Technology (SMiRT-14) / Livolant, M. [ed]},
  journal   = {Transactions of the 14th International Conference on Structural Dynamics in Reactor Technology (SMiRT-14) / Livolant, M. [ed]},
  address   = {Lyon},
  pages     = {33 -- 40},
  year      = {1997},
  language  = {en}
}
@inproceedings{BhattaraiFrotscherStaat2016,
  author    = {Bhattarai, Aroj and Frotscher, Ralf and Staat, Manfred},
  title     = {Significance of fibre geometry on passive-active response of pelvic muscles to evaluate pelvic dysfunction},
  series = {BioMedWomen: Proceedings of the international conference on clinical and bioengineering for women's health},
  booktitle = {BioMedWomen: Proceedings of the international conference on clinical and bioengineering for women's health},
  editor    = {Natal Jorge, Renato},
  publisher = {CRC Press},
  address   = {Boca Raton},
  isbn      = {978-1-138-02910-1},
  pages     = {185 -- 188},
  year      = {2016},
  language  = {en}
}
@inproceedings{FrotscherDuongStaat2015,
  author    = {Frotscher, Ralf and Duong, Minh Tuan and Staat, Manfred},
  title     = {Simulating beating cardiomyocytes with electromechanical coupling},
  series = {II. International Conference on Biomedical Technology : 28-30 October 2015 Hannover, Germany / T. Lenarz, P. Wriggers (Eds.)},
  booktitle = {II. International Conference on Biomedical Technology : 28-30 October 2015 Hannover, Germany / T. Lenarz, P. Wriggers (Eds.)},
  organization    = {International Conference on Biomedical Technology <2, 2015, Hannover>},
  pages     = {1 -- 2},
  year      = {2015},
  language  = {en}
}
@incollection{TranStaat2014,
  author    = {Tran, Thanh Ngoc and Staat, Manfred},
  title     = {Shakedown analysis of Reissner-Mindlin plates using the edge-based smoothed finite element method},
  series = {Direct methods for limit states in structures and materials / Dieter Weichert ; Alan Ponter, ed.},
  booktitle = {Direct methods for limit states in structures and materials / Dieter Weichert ; Alan Ponter, ed.},
  publisher = {Springer},
  address   = {Dordrecht [u.a.]},
  isbn      = {978-94-007-6826-0 (Print) 978-94-007-6827-7 (Online)},
  doi       = {10.1007/978-94-007-6827-7_5},
  pages     = {101 -- 117},
  year      = {2014},
  abstract  = {This paper concerns the development of a primal-dual algorithm for limit and shakedown analysis of Reissner-Mindlin plates made of von Mises material. At each optimization iteration, the lower bound of the shakedown load multiplier is calculated simultaneously with the upper bound using the duality theory. An edge-based smoothed finite element method (ES-FEM) combined with the discrete shear gap (DSG) technique is used to improve the accuracy of the solutions and to avoid the transverse shear locking behaviour. The method not only possesses all inherent features of convergence and accuracy from ES-FEM, but also ensures that the total number of variables in the optimization problem is kept to a minimum compared with the standard finite element formulation. Numerical examples are presented to demonstrate the effectiveness of the present method.},
  language  = {en}
}
@article{BhattaraiJabbariAndingetal.2018,
  author    = {Bhattarai, Aroj and Jabbari, Medisa and Anding, Ralf and Staat, Manfred},
  title     = {Surgical treatment of vaginal vault prolapse using different prosthetic mesh implants: a finite element analysis},
  series = {tm - Technisches Messen},
  volume    = {85},
  journal   = {tm - Technisches Messen},
  number    = {5},
  publisher = {De Gruyter},
  address   = {Berlin},
  issn      = {2196-7113},
  doi       = {10.1515/teme-2017-0115},
  pages     = {331 -- 342},
  year      = {2018},
  abstract  = {Particularly multiparous elderly women may suffer from vaginal vault prolapse after hysterectomy due to weak support from lax apical ligaments. A decreased amount of estrogen and progesterone in older age is assumed to remodel the collagen thereby reducing tissue stiffness. Sacrocolpopexy is either performed as open or laparoscopic surgery using prosthetic mesh implants to substitute lax ligaments. Y-shaped mesh models (DynaMesh, Gynemesh, and Ultrapro) are implanted in a 3D female pelvic floor finite element model in the extraperitoneal space from the vaginal cuff to the first sacral (S1) bone below promontory. Numerical simulations are conducted during Valsalva maneuver with weakened tissues modeled by reduced tissue stiffness. Tissues are modeled as incompressible, isotropic hyperelastic materials whereas the meshes are modeled either as orthotropic linear elastic or as isotropic hyperlastic materials. The positions of the vaginal cuff and the bladder base are calculated from the pubococcygeal line for female pelvic floor at rest, for prolapse and after repair using the three meshes. Due to mesh mechanics and mesh pore deformation along the loaded direction, the DynaMesh with regular rectangular mesh pores is found to provide better mechanical support to the organs than the Gynemesh and the Ultrapro with irregular hexagonal mesh pores. Insbesondere {\"a}ltere, mehrgeb{\"a}hrende Frauen leiden h{\"a}ufiger an einem Scheidenvorfall nach einer Hysterektomie aufgrund der schwachen Unterst{\"u}tzung durch laxe apikale B{\"a}nder. Es wird angenommen, dass eine verringerte Menge an {\"O}strogen und Progesteron im h{\"o}heren Alter das Kollagen umformt, wodurch die Gewebesteifigkeit reduziert wird. Die Sakrokolpopexie ist eine offene oder laparoskopische Operation, die mit prothetischen Netzimplantaten durchgef{\"u}hrt wird, um laxe B{\"a}nder zu ersetzen. Y-f{\"o}rmige Netzmodelle (DynaMesh, Gynemesh und Ultrapro) werden in einem 3D-Modell des weiblichen Beckenbodens im extraperitonealen Raum vom Vaginalstumpf bis zum Promontorium implantiert. Numerische Simulationen werden w{\"a}hrend des Valsalva-Man{\"o}vers mit geschw{\"a}chtem Gewebe durchgef{\"u}hrt, das durch eine reduzierte Gewebesteifigkeit modelliert wird. Die Gewebe werden als inkompressible, isotrop hyperelastische Materialien modelliert, w{\"a}hrend die Netze entweder als orthotrope linear elastische oder als isotrope hyperlastische Materialien modelliert werden. Die Positionen des Vaginalstumpfs, der Blase und der Harnr{\"o}hrenachse werden anhand der Pubococcygeallinie aus der Ruhelage, f{\"u}r den Prolaps und nach der Reparatur unter Verwendung der drei Netze berechnet. Aufgrund der Netzmechanik und der Netzporenverformung bietet das DynaMesh mit regelm{\"a}ßigen rechteckigen Netzporen eine bessere mechanische Unterst{\"u}tzung und eine Neupositionierung des Scheidengew{\"o}lbes, der Blase und der Urethraachse als Gynemesh und Ultrapro mit unregelm{\"a}ßigen hexagonalen Netzporen.},
  language  = {en}
}
@article{BirgelLeschingerWegmannetal.2018,
  author    = {Birgel, Stefan and Leschinger, Tim and Wegmann, Kilian and Staat, Manfred},
  title     = {Calculation of muscle forces and joint reaction loads in the shoulder area via an OpenSim based computer model},
  series = {tm - Technisches Messen},
  volume    = {85},
  journal   = {tm - Technisches Messen},
  number    = {5},
  publisher = {De Gruyter},
  address   = {Berlin},
  issn      = {2196-7113},
  doi       = {10.1515/teme-2017-0114},
  pages     = {321 -- 330},
  year      = {2018},
  abstract  = {Using the OpenSim software and verified anatomical data, a computer model for the calculation of biomechanical parameters is developed and used to determine the effect of a reattachment of the Supraspinatus muscle with a medial displacement of the muscle attachment point, which may be necessary for a rupture of the supraspinatus tendon. The results include the influence of the operation on basic biomechanical parameters such as the lever arm, as well as the calculated the muscle activations for the supraspinatus and deltoid. In addition, the influence on joint stability is examined by an analysis of the joint reaction force. The study provides a detailed description of the used model, as well as medical findings to a reattachment of the supraspinatus. Mit der Software OpenSim und {\"u}berpr{\"u}ften anatomischen Daten wird ein Computermodell zur Berechnung von biomechanischen Parametern entwickelt und genutzt, um den Effekt einer Refixierung des Supraspinatusmuskels mit einer medialen Verschiebung des Muskelansatzpunktes zu ermitteln, wie sie unter anderem nach einem Riss der Supraspinatussehne notwendig sein kann. Die Ergebnisse umfassen hierbei den Einfluss der Operation auf grundlegende biomechanische Parameter wie den Hebelarm sowie die berechneten Muskelaktivierungen f{\"u}r den Supraspinatus und Deltoideus. Zus{\"a}tzlich wird der Einfluss auf die Gelenkstabilit{\"a}t betrachtet und durch eine Analyse der Gelenkreaktionskraft untersucht. Die Studie bietet eine detaillierte Beschreibung des genutzten Modells, sowie medizinische Erkenntnisse zu einer Refixierung des Supraspinatus.},
  language  = {en}
}
@incollection{StaatHeitzer2003,
  author    = {Staat, Manfred and Heitzer, Michael},
  title     = {Probabilistic limit and shakedown problems},
  series = {Numerical methods for limit and shakedown analysis. Deterministic and probabilistic problems},
  volume    = {15},
  booktitle = {Numerical methods for limit and shakedown analysis. Deterministic and probabilistic problems},
  editor    = {Staat, Manfred and Heitzer, Michael},
  publisher = {John von Neumann Institute for Computing (NIC)},
  address   = {J{\"u}lich},
  isbn      = {3-00-010001-6},
  pages     = {217 -- 268},
  year      = {2003},
  language  = {en}
}
@inproceedings{DuongNguyenStaat2015,
  author    = {Duong, Minh Tuan and Nguyen, N. H. and Staat, Manfred},
  title     = {Modeling and simulation of a growing mass by the Smoothed Finite Element Method (SFEM)},
  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}
}
@inproceedings{StaatHeitzer1997,
  author    = {Staat, Manfred and Heitzer, Michael},
  title     = {Limit and shakedown analysis for plastic design},
  year      = {1997},
  abstract  = {Limit and shakedown theorems are exact theories of classical plasticity for the direct computation of safety factors or of the load carrying capacity under constant and varying loads. Simple versions of limit and shakedown analysis are the basis of all design codes for pressure vessels and pipings. Using Finite Element Methods more realistic modeling can be used for a more rational design. The methods can be extended to yield optimum plastic design. In this paper we present a first implementation in FE of limit and shakedown analyses for perfectly plastic material. Limit and shakedown analyses are done of a pipe-junction and a interaction diagram is calculated. The results are in good correspondence with the analytic solution we give in the appendix.},
  subject      = {Einspielen <Werkstoff>},
  language  = {en}
}
@article{RauschHarbrechtKahmannetal.2020,
  author    = {Rausch, Valentin and Harbrecht, Andreas and Kahmann, Stephanie Lucina and Fenten, Thomas and Jovanovic, Nebojsa and Hackl, Michael and M{\"u}ller, Lars P. and Staat, Manfred and Wegmann, Kilian},
  title     = {Osteosynthesis of Phalangeal Fractures: Biomechanical Comparison of Kirschner Wires, Plates, and Compression Screws},
  series = {The Journal of Hand Surgery},
  volume    = {45},
  journal   = {The Journal of Hand Surgery},
  number    = {10},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0363-5023},
  doi       = {10.1016/j.jhsa.2020.04.010},
  pages     = {987.e1 -- 987.e8},
  year      = {2020},
  abstract  = {Purpose The aim of this study was to compare several osteosynthesis techniques (intramedullary headless compression screws, T-plates, and Kirschner wires) for distal epiphyseal fractures of proximal phalanges in a human cadaveric model. Methods A total of 90 proximal phalanges from 30 specimens (index, ring, and middle fingers) were used for this study. After stripping off all soft tissue, a transverse distal epiphyseal fracture was simulated at the proximal phalanx. The 30 specimens were randomly assigned to 1 fixation technique (30 per technique), either a 3.0-mm intramedullary headless compression screw, locking plate fixation with a 2.0-mm T-plate, or 2 oblique 1.0-mm Kirschner wires. Displacement analysis (bending, distraction, and torsion) was performed using optical tracking of an applied random speckle pattern after osteosynthesis. Biomechanical testing was performed with increasing cyclic loading and with cyclic load to failure using a biaxial torsion-tension testing machine. Results Cannulated intramedullary compression screws showed significantly less displacement at the fracture site in torsional testing. Furthermore, screws were significantly more stable in bending testing. Kirschner wires were significantly less stable than plating or screw fixation in any cyclic load to failure test setup. Conclusions Intramedullary compression screws are a highly stable alternative in the treatment of transverse distal epiphyseal phalangeal fractures. Kirschner wires seem to be inferior regarding displacement properties and primary stability. Clinical relevance Fracture fixation of phalangeal fractures using plate osteosynthesis may have the advantage of a very rigid reduction, but disadvantages such as stiffness owing to the more invasive surgical approach and soft tissue irritation should be taken into account. Headless compression screws represent a minimally invasive choice for fixation with good biomechanical properties.},
  language  = {en}
}
@inproceedings{StaatHeitzer2000,
  author    = {Staat, Manfred and Heitzer, Michael},
  title     = {Direct static FEM approach to limit and shakedown analysis},
  year      = {2000},
  abstract  = {Safety and reliability of structures may be assessed indirectly by stress distributions. Limit and shakedown theorems are simplified but exact methods of plasticity that provide safety factors directly in the loading space. These theorems may be used for a direct definition of the limit state function for failure by plastic collapse or by inadaptation. In a FEM formulation the limit state function is obtained from a nonlinear optimization problem. This direct approach reduces considerably the necessary knowledge of uncertain technological input data, the computing time, and the numerical error. Moreover, the direct way leads to highly effective and precise reliability analyses. The theorems are implemented into a general purpose FEM program in a way capable of large-scale analysis.},
  subject      = {Einspielen <Werkstoff>},
  language  = {en}
}
@article{Staat2005,
  author    = {Staat, Manfred},
  title     = {Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels},
  year      = {2005},
  abstract  = {Limit loads can be calculated with the finite element method (FEM) for any component, defect geometry, and loading. FEM suggests that published long crack limit formulae for axial defects under-estimate the burst pressure for internal surface defects in thick pipes while limit loads are not conservative for deep cracks and for pressure loaded crack-faces. Very deep cracks have a residual strength, which is modelled by a global collapse load. These observations are combined to derive new analytical local and global collapse loads. The global collapse loads are close to FEM limit analyses for all crack dimensions.},
  subject      = {Finite-Elemente-Methode},
  language  = {en}
}
@inproceedings{TranStaatKreissig2007,
  author    = {Tran, Thanh Ngoc and Staat, Manfred and Kreißig, R.},
  title     = {Finite element shakedown and limit reliability analysis of thin shells},
  year      = {2007},
  abstract  = {A procedure for the evaluation of the failure probability of elastic-plastic thin shell structures is presented. The procedure involves a deterministic limit and shakedown analysis for each probabilistic iteration which is based on the kinematical approach and the use the exact Ilyushin yield surface. Based on a direct definition of the limit state function, the non-linear problems may be efficiently solved by using the First and Second Order Reliabiblity Methods (Form/SORM). This direct approach reduces considerably the necessary knowledge of uncertain technological input data, computing costs and the numerical error. In: Computational plasticity / ed. by Eugenio Onate. Dordrecht: Springer 2007. VII, 265 S. (Computational Methods in Applied Sciences ; 7) (COMPLAS IX. Part 1 . International Center for Numerical Methods in Engineering (CIMNE)). ISBN 978-1-402-06576-7 S. 186-189},
  subject      = {Finite-Elemente-Methode},
  language  = {en}
}
@article{Staat2004,
  author    = {Staat, Manfred},
  title     = {Plastic collapse analysis of longitudinally flawed pipes and vessels},
  year      = {2004},
  abstract  = {Improved collapse loads of thick-walled, crack containing pipes and vessels are suggested. Very deep cracks have a residual strength which is better modelled by a global limit load. In all burst tests, the ductility of pressure vessel steels was sufficiently high whereby the burst pressure could be predicted by limit analysis with no need to apply fracture mechanics. The relative prognosis error increases however, for long and deep defects due to uncertainties of geometry and strength data.},
  subject      = {Druckbeh{\"a}lter},
  language  = {en}
}
@inproceedings{DuongStaat2014,
  author    = {Duong, Minh Tuan and Staat, Manfred},
  title     = {A face-based smoothed finite element method for hyperelastic models and tissue growth},
  series = {11th World Congress on Computational Mechanics (WCCM XI) ; 5th European Conference on Computational Mechanics (ECCM V) ; 6th European Conference on Computational Fluid Dynamics (ECFD VI) ; July 20-25, 2014, Barcelona},
  booktitle = {11th World Congress on Computational Mechanics (WCCM XI) ; 5th European Conference on Computational Mechanics (ECCM V) ; 6th European Conference on Computational Fluid Dynamics (ECFD VI) ; July 20-25, 2014, Barcelona},
  editor    = {Onate, E.},
  organization    = {World Congress on Computational Mechanics <11, 2014, Barcelona>},
  pages     = {1 -- 12},
  year      = {2014},
  language  = {en}
}
@inproceedings{Staat2003,
  author    = {Staat, Manfred},
  title     = {Design by Analysis of Pressure Components by non-linear Optimization},
  year      = {2003},
  abstract  = {This paper presents the direct route to Design by Analysis (DBA) of the new European pressure vessel standard in the language of limit and shakedown analysis (LISA). This approach leads to an optimization problem. Its solution with Finite Element Analysis is demonstrated for some examples from the DBA-Manual. One observation from the examples is, that the optimisation approach gives reliable and close lower bound solutions leading to simple and optimised design decision.},
  language  = {en}
}
@article{StaatSchwartzLangetal.2003,
  author    = {Staat, Manfred and Schwartz, M. and Lang, H. and Wirtz, K. and Heitzer, M.},
  title     = {Design by Analysis of Pressure Components by non-linear Optimization},
  series = {The 10th International Conference on Pressure Vessel Technology, July 7-10, 2003, Vienna, Austria, Proceedings ICPVT-10 / Zeman, J. L. [ed]},
  journal   = {The 10th International Conference on Pressure Vessel Technology, July 7-10, 2003, Vienna, Austria, Proceedings ICPVT-10 / Zeman, J. L. [ed]},
  publisher = {{\"O}GS, {\"O}sterreichische Gesellschaft f{\"u}r Schweißtechnik},
  address   = {Wien},
  isbn      = {3950152814},
  pages     = {59 -- 65},
  year      = {2003},
  language  = {en}
}
@article{StaatHeitzer2002,
  author    = {Staat, Manfred and Heitzer, M.},
  title     = {Limit and Shakedown Analysis with Uncertain Data},
  series = {Stochastic optimization techniques : numerical methods and technical applications / Marti, K. [ed]},
  journal   = {Stochastic optimization techniques : numerical methods and technical applications / Marti, K. [ed]},
  publisher = {Springer},
  address   = {Heidelberg},
  isbn      = {3-540-42889-5},
  pages     = {241 -- 254},
  year      = {2002},
  language  = {en}
}