@article{Staat2021,
  author    = {Staat, Manfred},
  title     = {An extension strain type Mohr-Coulomb criterion},
  series = {Rock mechanics and rock engineering},
  volume    = {54},
  journal   = {Rock mechanics and rock engineering},
  number    = {12},
  publisher = {Springer Nature},
  address   = {Cham},
  issn      = {1434-453X},
  doi       = {10.1007/s00603-021-02608-7},
  pages     = {6207 -- 6233},
  year      = {2021},
  abstract  = {Extension fractures are typical for the deformation under low or no confining pressure. They can be explained by a phenomenological extension strain failure criterion. In the past, a simple empirical criterion for fracture initiation in brittle rock has been developed. In this article, it is shown that the simple extension strain criterion makes unrealistic strength predictions in biaxial compression and tension. To overcome this major limitation, a new extension strain criterion is proposed by adding a weighted principal shear component to the simple criterion. The shear weight is chosen, such that the enriched extension strain criterion represents the same failure surface as the Mohr-Coulomb (MC) criterion. Thus, the MC criterion has been derived as an extension strain criterion predicting extension failure modes, which are unexpected in the classical understanding of the failure of cohesive-frictional materials. In progressive damage of rock, the most likely fracture direction is orthogonal to the maximum extension strain leading to dilatancy. The enriched extension strain criterion is proposed as a threshold surface for crack initiation CI and crack damage CD and as a failure surface at peak stress CP. Different from compressive loading, tensile loading requires only a limited number of critical cracks to cause failure. Therefore, for tensile stresses, the failure criteria must be modified somehow, possibly by a cut-off corresponding to the CI stress. Examples show that the enriched extension strain criterion predicts much lower volumes of damaged rock mass compared to the simple extension strain criterion.},
  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{StaatDuong2016,
  author    = {Staat, Manfred and Duong, Minh Tuan},
  title     = {Smoothed Finite Element Methods for Nonlinear Solid Mechanics Problems: 2D and 3D Case Studies},
  series = {Proceedings of the National Science and Technology Conference on Mechanical - Transportation Engineering (NSCMET 2016), 13th October 2016, Hanoi, Vietnam, Vol.2},
  booktitle = {Proceedings of the National Science and Technology Conference on Mechanical - Transportation Engineering (NSCMET 2016), 13th October 2016, Hanoi, Vietnam, Vol.2},
  pages     = {440 -- 445},
  year      = {2016},
  abstract  = {The Smoothed Finite Element Method (SFEM) is presented as an edge-based and a facebased techniques for 2D and 3D boundary value problems, respectively. SFEMs avoid shortcomings of the standard Finite Element Method (FEM) with lower order elements such as overly stiff behavior, poor stress solution, and locking effects. Based on the idea of averaging spatially the standard strain field of the FEM over so-called smoothing domains SFEM calculates the stiffness matrix for the same number of degrees of freedom (DOFs) as those of the FEM. However, the SFEMs significantly improve accuracy and convergence even for distorted meshes and/or nearly incompressible materials. Numerical results of the SFEMs for a cardiac tissue membrane (thin plate inflation) and an artery (tension of 3D tube) show clearly their advantageous properties in improving accuracy particularly for the distorted meshes and avoiding shear locking effects.},
  language  = {en}
}
@inproceedings{DuongJungFrotscheretal.2016,
  author    = {Duong, Minh Tuan and Jung, Alexander and Frotscher, Ralf and Staat, Manfred},
  title     = {A 3D electromechanical FEM-based model for cardiac tissue},
  series = {ECCOMAS Congress 2016, VII European Congress on Computational Methods in Applied Sciences and Engineering. Crete Island, Greece, 5-10 June 2016},
  booktitle = {ECCOMAS Congress 2016, VII European Congress on Computational Methods in Applied Sciences and Engineering. Crete Island, Greece, 5-10 June 2016},
  editor    = {Papadrakakis, M.},
  pages     = {13 S.},
  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}
}
@inproceedings{FrotscherStaat2015,
  author    = {Frotscher, Ralf and Staat, Manfred},
  title     = {Homogenization of a cardiac tissue construct},
  series = {CMBE15 : 4th International Conference on Computational \& Mathematical Biomedical Engineering ; 29th June - 1st July 2015 ; {\´E}cole Normale Sup{\´e}rieure de Cachan ; Cachan (Paris), France},
  booktitle = {CMBE15 : 4th International Conference on Computational \& Mathematical Biomedical Engineering ; 29th June - 1st July 2015 ; {\´E}cole Normale Sup{\´e}rieure de Cachan ; Cachan (Paris), France},
  editor    = {Nithiarasu, Perumal},
  publisher = {CMBE},
  address   = {[s.l.]},
  issn      = {2227-9385},
  pages     = {645 -- 648},
  year      = {2015},
  language  = {en}
}
@inproceedings{TranStaatStavroulakis2014,
  author    = {Tran, Ngoc Trinh and Staat, Manfred and Stavroulakis, G. E.},
  title     = {A multicriteria method for truss optimization},
  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{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{TranStaat2014,
  author    = {Tran, Thanh Ngoc and Staat, Manfred},
  title     = {Uncertain multimode failure and limit analysis of shells},
  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{BhattaraiFrotscherSoraetal.2014,
  author    = {Bhattarai, Aroj and Frotscher, Ralf and Sora, M.-C. and Staat, Manfred},
  title     = {A 3D finite element model of the female pelvic floor for the reconstruction of urinary incontinence},
  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{JungStaatMueller2014,
  author    = {Jung, Alexander and Staat, Manfred and M{\"u}ller, Wolfram},
  title     = {Optimization of the flight style in ski jumping},
  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     = {799 -- 810},
  year      = {2014},
  language  = {en}
}
@inproceedings{FrotscherKochRaatschenetal.2014,
  author    = {Frotscher, Ralf and Koch, Jan-Peter and Raatschen, Hans-J{\"u}rgen and Staat, Manfred},
  title     = {Evaluation of a computational model for drug action on cardiac tissue},
  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}
}
@article{StaatHeitzer1997,
  author    = {Staat, Manfred and Heitzer, M.},
  title     = {Limit and Shakedown Analysis Using a General Purpose Finite Element Code},
  series = {Proceedings of NAFEMS World Congress '97 on Design, Simulation \& Optimisation : reliability \& applicability of computational methods ; Stuttgart, Germany, 9 - 11 April 1997},
  journal   = {Proceedings of NAFEMS World Congress '97 on Design, Simulation \& Optimisation : reliability \& applicability of computational methods ; Stuttgart, Germany, 9 - 11 April 1997},
  publisher = {NAFEMS},
  address   = {Glasgow},
  isbn      = {1-87437-620-4},
  pages     = {522 -- 533},
  year      = {1997},
  language  = {en}
}
@inproceedings{BurgazziFioriniDeMagistrisetal.1998,
  author    = {Burgazzi, L. and Fiorini, F. and De Magistris, W. (u.a.) and Lensa, W. von and Staat, Manfred and Altes, J.},
  title     = {Reliability Assessment of Passive Safety Systems},
  series = {Proceedings of the 6th International Conference on Nuclear Engineering : ICONE : May 10 - 14, 1998, San Diego, Calif.},
  booktitle = {Proceedings of the 6th International Conference on Nuclear Engineering : ICONE : May 10 - 14, 1998, San Diego, Calif.},
  publisher = {American Society of Mechanical Engineers},
  address   = {New York},
  year      = {1998},
  language  = {en}
}
@inproceedings{TranNovacekTolbaetal.2011,
  author    = {Tran, Thanh Ngoc and Novacek, V. and Tolba, R. and Klinge, U. and Turquier, F. and Staat, Manfred},
  title     = {Experimental and Computational approach to study colorectal anastomosis. ISB2011, Proceedings of the XXIII Congress of the International Society of Biomechanics, Brussels, Belgium, July 3-7, 2011},
  year      = {2011},
  abstract  = {Summary: This paper presents a methodology to study and understand the mechanics of stapled anastomotic behaviors by combining empirical experimentation and finite element analysis. Performance of stapled anastomosis is studied in terms of leakage and numerical results which are compared to in vitro experiments performed on fresh porcine tissue. Results suggest that leaks occur between the tissue and staple legs penetrating through the tissue.},
  subject      = {Anastomose},
  language  = {en}
}
@article{StaatBallmann1988,
  author    = {Staat, Manfred and Ballmann, J.},
  title     = {Computation of impacts on elastic solids by methods of bicharacteristics},
  series = {Computational Mechanics '88 : theory and applications ; proceedings of the International Conference on Computational Engineering Science April 10-14, 1988, Atlanta, GA, USA ; vol. 2},
  journal   = {Computational Mechanics '88 : theory and applications ; proceedings of the International Conference on Computational Engineering Science April 10-14, 1988, Atlanta, GA, USA ; vol. 2},
  pages     = {1719 -- 1722},
  year      = {1988},
  abstract  = {Shock waves, explosions, impacts or cavitation bubble collapses may generate stress waves in solids causing cracks or unexpected dammage due to focussing, physical nonlinearity or interaction with existing cracks. There is a growing interest in wave propagation, which poses many novel problems to experimentalists and theorists.},
  subject      = {Bicharakteristikenverfahren},
  language  = {en}
}
@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}
}
@inproceedings{StaatTranPham2008,
  author    = {Staat, Manfred and Tran, Thanh Ngoc and Pham, Phu Tinh},
  title     = {Limit and shakedown reliability analysis by nonlinear programming},
  year      = {2008},
  abstract  = {7th International Conference on Reliability of Materials and Structures (RELMAS 2008). June 17 - 20, 2008 ; Saint Petersburg, Russia. pp 354-358. Reprint with corrections in red Introduction Analysis of advanced structures working under extreme heavy loading such as nuclear power plants and piping system should take into account the randomness of loading, geometrical and material parameters. The existing reliability are restricted mostly to the elastic working regime, e.g. allowable local stresses. Development of the limit and shakedown reliability-based analysis and design methods, exploiting potential of the shakedown working regime, is highly needed. In this paper the application of a new algorithm of probabilistic limit and shakedown analysis for shell structures is presented, in which the loading and strength of the material as well as the thickness of the shell are considered as random variables. The reliability analysis problems may be efficiently solved by using a system combining the available FE codes, a deterministic limit and shakedown analysis, and the First and Second Order Reliability Methods (FORM/SORM). Non-linear sensitivity analyses are obtained directly from the solution of the deterministic problem without extra computational costs.},
  subject      = {Finite-Elemente-Methode},
  language  = {en}
}
@inproceedings{TranPhamStaat2008,
  author    = {Tran, Thanh Ngoc and Pham, Phu Tinh and Staat, Manfred},
  title     = {Reliability analysis of shells based on direct plasticity methods},
  year      = {2008},
  abstract  = {Abstracts der CD-Rom Proceedings of the 8th World Congress on Computational Mechanics (WCCM8) and 5th Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2008) 30.06. - 04.07.2008 Venedig, Italien. 2 Seiten Zusammenfassung der Autoren mit graph. Darst. und Literaturverzeichnis},
  subject      = {Finite-Elemente-Methode},
  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}
}