@inproceedings{Dachwald2017,
  author    = {Dachwald, Bernd},
  title     = {Radiation pressure force model for an ideal laser-enhanced solar sail},
  series = {4th International Symposium on Solar Sailing},
  booktitle = {4th International Symposium on Solar Sailing},
  pages     = {1 -- 5},
  year      = {2017},
  abstract  = {The concept of a laser-enhanced solar sail is introduced and the radiation pressure force model for an ideal laser-enhanced solar sail is derived. A laser-enhanced solar sail is a "traditional" solar sail that is, however, not solely propelled by solar radiation, but additionally by a laser beam that illuminates the sail. The additional laser radiation pressure increases the sail's propulsive force and can give, depending on the location of the laser source, more control authority over the direction of the solar sail's propulsive force vector. This way, laser-enhanced solar sails may augment already existing solar sail mission concepts and make novel mission concepts feasible.},
  language  = {en}
}
@inproceedings{PhamStaat2015,
  author    = {Pham, Phu Tinh and Staat, Manfred},
  title     = {A simplification for shakedown analysis of hardening structures},
  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}
}
@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}
}
@article{LeschingerBirgelHackletal.2019,
  author    = {Leschinger, Tim and Birgel, Stefan and Hackl, Michael and Staat, Manfred and M{\"u}ller, Lars Peter and Wegmann, Kilian},
  title     = {A musculoskeletal shoulder simulation of moment arms and joint reaction forces after medialization of the supraspinatus footprint in rotator cuff repair},
  series = {Computer Methods in Biomechanics and Biomedical Engineering},
  journal   = {Computer Methods in Biomechanics and Biomedical Engineering},
  number    = {Early view},
  publisher = {Taylor \& Francis},
  address   = {London},
  doi       = {10.1080/10255842.2019.1572749},
  year      = {2019},
  language  = {en}
}
@incollection{DachwaldOhndorf2019,
  author    = {Dachwald, Bernd and Ohndorf, Andreas},
  title     = {Global optimization of continuous-thrust trajectories using evolutionary neurocontrol},
  series = {Modeling and Optimization in Space Engineering},
  booktitle = {Modeling and Optimization in Space Engineering},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-030-10501-3},
  doi       = {10.1007/978-3-030-10501-3_2},
  pages     = {33 -- 57},
  year      = {2019},
  abstract  = {Searching optimal continuous-thrust trajectories is usually a difficult and time-consuming task. The solution quality of traditional optimal-control methods depends strongly on an adequate initial guess because the solution is typically close to the initial guess, which may be far from the (unknown) global optimum. Evolutionary neurocontrol attacks continuous-thrust optimization problems from the perspective of artificial intelligence and machine learning, combining artificial neural networks and evolutionary algorithms. This chapter describes the method and shows some example results for single- and multi-phase continuous-thrust trajectory optimization problems to assess its performance. Evolutionary neurocontrol can explore the trajectory search space more exhaustively than a human expert can do with traditional optimal-control methods. Especially for difficult problems, it usually finds solutions that are closer to the global optimum. Another fundamental advantage is that continuous-thrust trajectories can be optimized without an initial guess and without expert supervision.},
  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{DachwaldBaturkinCoverstoneetal.2005,
  author    = {Dachwald, Bernd and Baturkin, Volodymyr and Coverstone, Victoria and Diedrich, Ben and Garbe, Gregory and G{\"o}rlich, Marianne and Leipold, Manfred and Lura, Franz and Macdonald, Malcolm and McInnes, Colin and Mengali, Giovanni and Quarta, Alessandro and Rios-Reyes, Leonel and Scheeres, Daniel J. and Seboldt, Wolfgang and Wie, Bong},
  title     = {Potential effects of optical solar sail degredation on trajectory design},
  series = {AAS/AIAA Astrodynamics Specialist},
  booktitle = {AAS/AIAA Astrodynamics Specialist},
  pages     = {1 -- 23},
  year      = {2005},
  abstract  = {The optical properties of the thin metalized polymer films that are projected for solar sails are assumed to be affected by the erosive effects of the space environment. Their degradation behavior in the real space environment, however, is to a considerable degree indefinite, because initial ground test results are controversial and relevant inspace tests have not been made so far. The standard optical solar sail models that are currently used for trajectory design do not take optical degradation into account, hence its potential effects on trajectory design have not been investigated so far. Nevertheless, optical degradation is important for high-fidelity solar sail mission design, because it decreases both the magnitude of the solar radiation pressure force acting on the sail and also the sail control authority. Therefore, we propose a simple parametric optical solar sail degradation model that describes the variation of the sail film's optical coefficients with time, depending on the sail film's environmental history, i.e., the radiation dose. The primary intention of our model is not to describe the exact behavior of specific film-coating combinations in the real space environment, but to provide a more general parametric framework for describing the general optical degradation behavior of solar sails. Using our model, the effects of different optical degradation behaviors on trajectory design are investigated for various exemplary missions.},
  language  = {en}
}
@article{Dachwald2004,
  author    = {Dachwald, Bernd},
  title     = {Low-Thrust Trajectory Optimization and Interplanetary Mission Analysis Using Evolutionary Neurocontrol},
  series = {Deutscher Luft- und Raumfahrtkongress 2004 : Dresden, 20. bis 23. September 2004, Motto: Luft- und Raumfahrt - Br{\"u}cke f{\"u}r eine wissensbasierte Gesellschaft / Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt - Lilienthal-Oberth e.V. (DGLR). [Red.: Peter Brandt (verantwortlich)]. - Bd. 2. - (Jahrbuch ... der Deutschen Gesellschaft f{\"u}r Luft- und Raumfahrt)},
  journal   = {Deutscher Luft- und Raumfahrtkongress 2004 : Dresden, 20. bis 23. September 2004, Motto: Luft- und Raumfahrt - Br{\"u}cke f{\"u}r eine wissensbasierte Gesellschaft / Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt - Lilienthal-Oberth e.V. (DGLR). [Red.: Peter Brandt (verantwortlich)]. - Bd. 2. - (Jahrbuch ... der Deutschen Gesellschaft f{\"u}r Luft- und Raumfahrt)},
  address   = {Bonn},
  pages     = {917 -- 926},
  year      = {2004},
  language  = {en}
}
@article{LoebSchartnerDachwaldetal.2012,
  author    = {Loeb, Horst Wolfgang and Schartner, Karl-Heinz and Dachwald, Bernd and Ohndorf, Andreas and Seboldt, Wolfgang},
  title     = {Interstellar heliopause probe},
  series = {Труды МАИ},
  journal   = {Труды МАИ},
  number    = {60},
  publisher = {Moskauer Staatliches Luftfahrtinstitut (МАИ)},
  address   = {Moskau},
  pages     = {2 -- 2},
  year      = {2012},
  abstract  = {There is common agreement within the scientific community that in order to understand our local galactic environment it will be necessary to send a spacecraft into the region beyond the solar wind termination shock. Considering distances of 200 AU for a new mission, one needs a spacecraft traveling at a speed of close to 10 AU/yr in order to keep the mission duration in the range of less than 25 yrs, a transfer time postulated by European Space Agency (ESA). Two propulsion options for the mission have been proposed and discussed so far: the solar sail propulsion and the ballistic/radioisotope-electric propulsion (REP). As a further alternative, we here investigate a combination of solar-electric propulsion (SEP) and REP. The SEP stage consists of six 22-cms diameter RIT-22 ion thrusters working with a high specific impulse of 7377 s corresponding to a positive grid voltage of 5 kV. Solar power of 53 kW at begin of mission (BOM) is provided by a lightweight solar array.},
  language  = {en}
}
@misc{TopcuMadabhushiStaat2022,
  author    = {Topcu, Murat and Madabhushi, Gopal Santana Phani and Staat, Manfred},
  title     = {Datasets from FEM Simulations done with COMSOL Multiphysics and Code_Aster},
  doi       = {10.6084/m9.figshare.19333295.v2},
  year      = {2022},
  abstract  = {Datasets from FEM Simulations done with COMSOL Multiphysics and Code_Aster for an elastic stress transfer between matrix and fibres having a variable radius.},
  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{PogorelovaRogachevDigeletal.2020,
  author    = {Pogorelova, Natalia and Rogachev, Evgeniy and Digel, Ilya and Chernigova, Svetlana and Nardin, Dmitry},
  title     = {Bacterial Cellulose Nanocomposites: Morphology and Mechanical Properties},
  series = {Materials},
  volume    = {13},
  journal   = {Materials},
  number    = {12},
  publisher = {MDPI},
  address   = {Basel},
  isbn      = {1996-1944},
  doi       = {10.3390/ma13122849},
  pages     = {1 -- 16},
  year      = {2020},
  abstract  = {Bacterial cellulose (BC) is a promising material for biomedical applications due to its unique properties such as high mechanical strength and biocompatibility. This article describes the microbiological synthesis, modification, and characterization of the obtained BC-nanocomposites originating from symbiotic consortium Medusomyces gisevii. Two BC-modifications have been obtained: BC-Ag and BC-calcium phosphate (BC-Ca3(PO4)2). Structure and physicochemical properties of the BC and its modifications were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and infrared Fourier spectroscopy as well as by measurements of mechanical and water holding/absorbing capacities. Topographic analysis of the surface revealed multicomponent thick fibrils (150-160 nm in diameter and about 15 µm in length) constituted by 50-60 nm nanofibrils weaved into a left-hand helix. Distinctive features of Ca-phosphate-modified BC samples were (a) the presence of 500-700 nm entanglements and (b) inclusions of Ca3(PO4)2 crystals. The samples impregnated with Ag nanoparticles exhibited numerous roundish inclusions, about 110 nm in diameter. The boundaries between the organic and inorganic phases were very distinct in both cases. The Ag-modified samples also showed a prominent waving pattern in the packing of nanofibrils. The obtained BC gel films possessed water-holding capacity of about 62.35 g/g. However, the dried (to a constant mass) BC-films later exhibited a low water absorption capacity (3.82 g/g). It was found that decellularized BC samples had 2.4 times larger Young's modulus and 2.2 times greater tensile strength as compared to dehydrated native BC films. We presume that this was caused by molecular compaction of the BC structure.},
  language  = {en}
}
@article{DachwaldSeboldtRichter2003,
  author    = {Dachwald, Bernd and Seboldt, Wolfgang and Richter, L.},
  title     = {Multiple Rendezvous and Sample Return Missions to Near-Earth Asteroids Using Solar Sailcraft},
  series = {Proceedings of the Fifth IAA International Conference on Low Cost Planetary Missions : 24 - 26 September 2003, ESTEC, Noordwijk, the Netherlands / [comp. by R. A. Harris]},
  journal   = {Proceedings of the Fifth IAA International Conference on Low Cost Planetary Missions : 24 - 26 September 2003, ESTEC, Noordwijk, the Netherlands / [comp. by R. A. Harris]},
  publisher = {ESA},
  address   = {Noordwijk},
  isbn      = {92-9092-853-0},
  pages     = {351 -- 358},
  year      = {2003},
  language  = {en}
}
@inproceedings{StaatTran2022,
  author    = {Staat, Manfred and Tran, Ngoc Trinh},
  title     = {Strain based brittle failure criteria for rocks},
  series = {Proceedings of (NACOME2022) The 11th National Conference on Mechanics, Vol. 1. Solid Mechanics, Rock Mechanics, Artificial Intelligence, Teaching and Training},
  booktitle = {Proceedings of (NACOME2022) The 11th National Conference on Mechanics, Vol. 1. Solid Mechanics, Rock Mechanics, Artificial Intelligence, Teaching and Training},
  publisher = {Nha xuat ban Khoa hoc tu nhien va Cong nghe (Verlag Naturwissenschaft und Technik)},
  address   = {Hanoi},
  isbn      = {978-604-357-084-7},
  pages     = {500 -- 509},
  year      = {2022},
  abstract  = {When confining pressure is low or absent, extensional fractures are typical, with fractures occurring on unloaded planes in rock. These "paradox" fractures 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. But this criterion makes unrealistic strength predictions in biaxial compression and tension. A new extension strain criterion overcomes this limitation by adding a weighted principal shear component. The 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 failure modes, which are unexpected in the 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. 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 P. 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}
}
@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}
}
@incollection{ArtmannMeruvuKizildagetal.2018,
  author    = {Artmann, Gerhard and Meruvu, Haritha and Kizildag, Sefa and Temiz Artmann, Ayseg{\"u}l},
  title     = {Functional Toxicology and Pharmacology Test of Cell Induced Mechanical Tensile Stress in 2D and 3D Tissue Cultures},
  series = {Biological, Physical and Technical Basics of Cell Engineering},
  booktitle = {Biological, Physical and Technical Basics of Cell Engineering},
  editor    = {Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l and Zhubanova, Azhar A. and Digel, Ilya},
  publisher = {Springer},
  address   = {Singapore},
  isbn      = {978-981-10-7904-7},
  doi       = {10.1007/978-981-10-7904-7_7},
  pages     = {157 -- 192},
  year      = {2018},
  abstract  = {Mechanical forces/tensile stresses are critical determinants of cellular growth, differentiation and migration patterns in health and disease. The innovative "CellDrum technology" was designed for measuring mechanical tensile stress of cultured cell monolayers/thin tissue constructs routinely. These are cultivated on very thin silicone membranes in the so-called CellDrum. The cell layers adhere firmly to the membrane and thus transmit the cell forces generated. A CellDrum consists of a cylinder which is sealed from below with a 4 μm thick, biocompatible, functionalized silicone membrane. The weight of cell culture medium bulbs the membrane out downwards. Membrane indentation is measured. When cells contract due to drug action, membrane, cells and medium are lifted upwards. The induced indentation changes allow for lateral drug induced mechanical tension quantification of the micro-tissues. With hiPS-induced (human) Cardiomyocytes (CM) the CellDrum opens new perspectives of individualized cardiac drug testing. Here, monolayers of self-beating hiPS-CMs were grown in CellDrums. Rhythmic contractions of the hiPS-cells induce membrane up-and-down deflections. The recorded cycles allow for single beat amplitude, single beat duration, integration of the single beat amplitude over the beat time and frequency analysis. Dose effects of agonists and antagonists acting on Ca2+ channels were sensitively and highly reproducibly observed. Data were consistent with published reference data as far as they were available. The combination of the CellDrum technology with hiPS-Cardiomyocytes offers a fast, facile and precise system for pharmacological and toxicological studies. It allows new preclinical basic as well as applied research in pharmacolgy and toxicology.},
  language  = {en}
}