TY  - JOUR
A1  - Staat, Manfred
A1  - Heitzer, M.
A1  - Reiners, H.
A1  - Schubert, F.
T1  - Shakedown and ratchetting under tension–torsion loadings: analysis and experiments
JF  - Nuclear Engineering and Design. 225 (2003), H. 1
Y1  - 2003
SN  - 0029-5493
SP  - 11
EP  - 26
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Schwartz, M.
A1  - Lang, H.
A1  - Wirtz, K.
A1  - Heitzer, M.
T1  - Design by Analysis of Pressure Components by non-linear Optimization
JF  - The 10th International Conference on Pressure Vessel Technology, July 7-10, 2003, Vienna, Austria, Proceedings ICPVT-10 / Zeman, J. L. [ed]
Y1  - 2003
SN  - 3950152814
SP  - 59
EP  - 65
PB  - ÖGS, Österreichische Gesellschaft für Schweißtechnik
CY  - Wien
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Heitzer, M.
T1  - Probabilistic limit and shakedown problems
JF  - Numerical Methods for Limit and Shakedown Analysis. Deterministic and Probabilistic Approach. NIC Series Vol. 15 / Ed. by Staat, M; Heitzer, M.
Y1  - 2003
SN  - 3-00-010001-6
SP  - 217
EP  - 268
PB  - John von Neumann Institute for Computing (NIC)
CY  - Jülich
ER  - 
TY  - JOUR
A1  - Staat, Manfred
T1  - Shakedown and ratchetting under tension-torsion loadings: analysis and experiments
N2  - Structural design analyses are conducted with the aim of verifying the exclusion of ratchetting. To this end it is important to make a clear distinction between the shakedown range and the ratchetting range. The performed experiment comprised a hollow tension specimen which was subjected to alternating axial forces, superimposed with constant moments. First, a series of uniaxial tests has been carried out in order to calibrate a bounded kinematic hardening rule. The load parameters have been selected on the basis of previous shakedown analyses with the PERMAS code using a kinematic hardening material model. It is shown that this shakedown analysis gives reasonable agreement between the experimental and the numerical results. A linear and a nonlinear kinematic hardening model of two-surface plasticity are compared in material shakedown analysis.
KW  - Einspielen <Werkstoff>
KW  - Einspielen
KW  - Ratchetting
KW  - Zug-Druck Belastung
KW  - shakedown
KW  - ratchetting
KW  - tension–torsion loading
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Staat, Manfred
T1  - Plastic collapse analysis of longitudinally flawed pipes and vessels
JF  - Nuclear Engineering and Design. 234 (2004), H. 1-3
Y1  - 2004
SN  - 0029-5493
SP  - 25
EP  - 43
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Vu, Duc-Khoi
T1  - An Algorithm for Shakedown Analysis for Materials with Temperature Dependent Yield Stress
JF  - Proceedings in Applied Mathematics and Mechanics (PAMM). 4 (2004), H. 1
Y1  - 2004
SN  - 1617-7061
SP  - 231
EP  - 233
ER  - 
TY  - JOUR
A1  - Staat, Manfred
T1  - Plastic collapse analysis of longitudinally flawed pipes and vessels
N2  - 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.
KW  - Druckbehälter
KW  - Stahl
KW  - Druckbelastung
KW  - Druckbeanspruchung
KW  - Rohr
KW  - Rohrbruch
KW  - Druckbehälter
KW  - Stahl
KW  - Druckbelastung
KW  - Druckbeanspruchung
KW  - Rohrbruch
KW  - Fehlerstellen
KW  - pipes
KW  - vessels
KW  - load limit
KW  - burst tests
KW  - burst pressure
KW  - flaw
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Vu, Duc-Khoi
A1  - Staat, Manfred
T1  - An algorithm for shakedown analysis of structure with temperature dependent yield stress
N2  - 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.
KW  - Einspielen <Werkstoff>
KW  - Temperaturabhängigkeit
KW  - Fließgrenze
KW  - Shakedown
KW  - shakedown analysis
KW  - yield stress
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Kühn, Raoul-Roman
A1  - Haugner, Werner
A1  - Staat, Manfred
A1  - Sponagel, Stefan
T1  - A Two Phase Mixture Model based on Bone Observation
N2  - An optimization method is developed to describe the mechanical behaviour of the human cancellous bone. The method is based on a mixture theory. A careful observation of the behaviour of the bone material leads to the hypothesis that the bone density is controlled by the principal stress trajectories (Wolff’s law). The basic idea of the developed method is the coupling of a scalar value via an eigenvalue problem to the principal stress trajectories. On the one hand this theory will permit a prediction of the reaction of the biological bone structure after the implantation of a prosthesis, on the other hand it may be useful in engineering optimization problems. An analytical example shows its efficiency.
KW  - Knochen
KW  - Knochenbildung
KW  - Knochenchirugie
KW  - Strukturanalyse
KW  - Schwammknochen
KW  - Knochendichte
KW  - Wolffsches Gesetz
KW  - bone structure
KW  - bone density
KW  - Wolff's Law
KW  - cancellous bone
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Heitzer, M.
A1  - Lang, H.
A1  - Wirtz, K.
T1  - Direct Finite Element Route for Design-by-Analysis of Pressure Components
JF  - International Journal of Pressure Vessels and Piping. 82 (2005), H. 1
Y1  - 2005
SN  - 0308-0161
SP  - 61
EP  - 67
ER  - 
TY  - JOUR
A1  - Staat, Manfred
T1  - Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels
JF  - International Journal of Pressure Vessels and Piping. 82 (2005), H. 3
Y1  - 2005
SN  - 0308-0161
SP  - 217
EP  - 225
ER  - 
TY  - JOUR
A1  - Staat, Manfred
T1  - Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels
N2  - 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.
KW  - Finite-Elemente-Methode
KW  - Grenzwertberechnung
KW  - Axialbelastung
KW  - FEM
KW  - Grenzwertberechnung
KW  - Axialbelastung
KW  - Traglastanalyse
KW  - Limit analysis
KW  - Global and local collapse
KW  - Axially cracked pipe
KW  - Pressure loaded crack-face
Y1  - 2005
ER  - 
TY  - JOUR
A1  - Staat, Manfred
T1  - Direct finite element route for design-by-analysis of pressure components
N2  - In the new European standard for unfired pressure vessels, EN 13445-3, there are two approaches for carrying out a Design-by-Analysis that cover both the stress categorization method (Annex C) and the direct route method (Annex B) for a check against global plastic deformation and against progressive plastic deformation. This paper presents the direct route in the language of limit and shakedown analysis. This approach leads to an optimization problem. Its solution with Finite Element Analysis is demonstrated for mechanical and thermal actions. One observation from the examples is that the so-called 3f (3Sm) criterion fails to be a reliable check against progressive plastic deformation. Precise conditions are given, which greatly restrict the applicability of the 3f criterion.
KW  - Einspielen <Werkstoff>
KW  - Plastizität
KW  - Deformation
KW  - Analytischer Zulaessigkeitsnachweis
KW  - Einspiel-Analyse
KW  - fortschreitende plastische Deformation
KW  - alternierend Verformbarkeit
KW  - Einspiel-Kriterium
KW  - Design-by-analysis
KW  - Shakedown analysis
KW  - Progressive plastic deformation
KW  - Alternating plasticity
KW  - Shakedown criterion
Y1  - 2005
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Vu, Khoi Duc
T1  - Limit loads of circumferentially flawed pipes and cylindrical vessels under internal pressure
JF  - International Journal of Pressure Vessels and Piping. 83 (2006), H. 3
Y1  - 2006
SN  - 0308-0161
SP  - 188
EP  - 196
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Vu, Duc-Khoi
T1  - Limit analysis of flaws in pressurized pipes and cylindrical vessels. Part I: Axial defects
JF  - Engineering Fracture Mechanics. 74 (2007), H. 3
Y1  - 2007
SN  - 0013-7944
SP  - 431
EP  - 450
ER  - 
TY  - JOUR
A1  - Vu, Duc Khoi
A1  - Staat, Manfred
A1  - Tran, Ich Thinh
T1  - Analysis of pressure equipment by application of the primal-dual theory of shakedown
JF  - Communications in Numerical Methods in Engineering. 23 (2007), H. 3
Y1  - 2007
SN  - 1069-8299
SP  - 213
EP  - 225
ER  - 
TY  - JOUR
A1  - Vu, Duc Khoi
A1  - Staat, Manfred
T1  - Shakedown analysis of structures made of materials with temperature-dependent yield stress
JF  - International Journal of Solids and Structures. 44 (2007), H. 13
Y1  - 2007
SN  - 0020-7683
SP  - 4524
EP  - 4540
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Baroud, G.
A1  - Topcu, M.
A1  - Sponagel, Stefan
T1  - Soft Materials in Technology and Biology – Characteristics, Properties, and Parameter Identification
JF  - Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.)
Y1  - 2008
SN  - 978-3-540-75408-4
SP  - 253
EP  - 315
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Vant, Christianne
A1  - Staat, Manfred
A1  - Baroud, Gamal
T1  - Percutaneous Vertebroplasty: A Review of Two Intraoperative Complications
JF  - Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.)
Y1  - 2008
SN  - 978-3-540-75408-4
SP  - 527
EP  - 539
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Tran, Thanh Ngoc
A1  - Kreißig, R.
A1  - Vu, Duc Khoi
A1  - Staat, Manfred
T1  - Upper bound limit and shakedown analysis of shells using the exact Ilyushin yield surface
JF  - Computer & Structures. 86 (2008)
Y1  - 2008
SN  - 0045-7949
SP  - 1683
EP  - 1695
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Tran, Thanh Ngoc
A1  - Kreißig, R.
T1  - Load bearing capacity of thin shell structures made of elastoplastic material by direct methods
JF  - Technische Mechanik. 28 (2008), H. 3-4
Y1  - 2008
SP  - 299
EP  - 309
ER  - 
TY  - JOUR
A1  - Ciobanu, Octavian
A1  - Staat, Manfred
A1  - Rahimi, Alireza
T1  - The use of open source software in biomechanical finite element analysis
JF  - Buletinul Institutului Politehnic din Iaşi / Universitatea Tehnică Gh. Asachi, Iaşi Secţia 5, Construcţii de maşini = Machine construction = Bulletin of the Polytechnic Institute of Jassy = Izvestija Jasskogo Politechničeskogo Instituta
Y1  - 2008
SN  - 1011-2855
VL  - 54
IS  - 7/8
SP  - 213
EP  - 220
ER  - 
TY  - JOUR
A1  - Tran, Thanh Ngoc
A1  - Kreißig, R.
A1  - Staat, Manfred
T1  - Probabilistic limit and shakedown analysis of thin plates and shells
JF  - Structural safety. 31 (2009), H. 1
Y1  - 2009
SN  - 0167-4730
SP  - 1
EP  - 18
PB  - -
ER  - 
TY  - JOUR
A1  - Tran, Thanh Ngoc
A1  - Pham, Phu Tinh
A1  - Vu, D. K.
A1  - Staat, Manfred
T1  - Reliability Analysis of Inelastic Shell Structures Under Variable Loads
JF  - Limit States of Materials and Structures : Direct Methods / Hrsg. Dieter Weichert; Hrsg. Alan Ponter
Y1  - 2009
SN  - 978-1-4020-9633-4
SP  - 135
EP  - 156
PB  - Springer Netherland
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Ullrich, Sebastian
A1  - Grottke, Oliver
A1  - Rossaint, Rolf
A1  - Staat, Manfred
A1  - Deserno, Thomas M.
A1  - Kuhlen, Torsten
T1  - Virtual Needle Simulation with Haptics for Regional Anaesthesia
Y1  - 2010
N1  - IEEE Virtual Reality 2010, Workshop on Medical Virtual Environments, Waltham, MA, USA, March 21, 2010
SP  - 1
EP  - 3
ER  - 
TY  - JOUR
A1  - Nguyen, N.-H.
A1  - Raatschen, Hans-Jürgen
A1  - Staat, Manfred
T1  - A hyperelastic model of biological tissue materials in tubular organs
Y1  - 2010
N1  - ECCM 2010, IV European Conference on Computational Mechanics, Paris, France, May 16-21, 2010.
SP  - 1
EP  - 12
ER  - 
TY  - JOUR
A1  - Pham, Phu Tinh
A1  - Vu, Khoi Duc
A1  - Tran, Thanh Ngoc
A1  - Staat, Manfred
T1  - A primal-dual algorithm for shakedown analysis of elastic-plastic bounded linearly kinematic hardening bodies
Y1  - 2010
N1  - ECCM 2010, IV European Conference on Computational Mechanics, Paris, France, May 16-21, 2010.
SP  - 1
EP  - 7
ER  - 
TY  - JOUR
A1  - Tran, Thanh Ngoc
A1  - Staat, Manfred
T1  - Shakedown analysis of two dimensional structures by an edge-based smoothed finite element method
Y1  - 2010
N1  - ECCM 2010, IV European Conference on Computational Mechanics, Paris, France, May 16-21, 2010.
SP  - 1
EP  - 7
ER  - 
TY  - JOUR
A1  - Grottke, O.
A1  - Braunschweig, T.
A1  - Philippen, B.
A1  - Gatzweiler, Karl-Heinz
A1  - Gronloh, N.
A1  - Staat, Manfred
A1  - Rossaint, R.
A1  - Tolba, R.
T1  - A New Model for Blunt Liver Injuries in the Swine
JF  - European Surgical Research. 44 (2010), H. 2
Y1  - 2010
SN  - 1421-9921
SP  - 65
EP  - 73
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Sponagel, Stefan
A1  - Nguyen, Nhu Huynh
T1  - Experiment and material model for soft tissue materials
JF  - Constitutive  models for rubber VI : proceedings of the sixth European Conference on Constitutive Models for Rubber, Dresden, Germany, 7 - 10 September 2009 / eds. Gert Heinrich ...
Y1  - 2010
SN  - 978-0-415-56327-7
SP  - 465
EP  - 470
PB  - CRC Press
CY  - Boca Raton [u.a.]
ER  - 
TY  - JOUR
A1  - Doorschodt, B. M.
A1  - Schreinemachers, M. C. J. M.
A1  - Behbahani, Mehdi
A1  - Florquin, S.
A1  - Weis, J.
A1  - Staat, Manfred
A1  - Tolba, R. H.
T1  - Hypothermic machine perfusion of kidney grafts: which pressure is preferred
JF  - Annals of Biomedical Engineering. 39 (2011), H. 3
Y1  - 2011
SN  - 1573-9686
SP  - 1051
EP  - 1059
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Vu, Duc Khoi
T1  - Limit analysis of flaws in pressurized pipes and cylindrical vessels Part II: Circumferential defects
JF  - Engineering Fracture Mechanics ; 97(2013), H. 1
N2  - Upper and lower bound theorems of limit analyses have been presented in part I of the paper. Part II starts with the finite element discretization of these theorems and demonstrates how both can be combined in a primal–dual optimization problem. This recently proposed numerical method is used to guide the development of a new class of closed-form limit loads for circumferential defects, which show that only large defects contribute to plastic collapse with a rapid loss of strength with increasing crack sizes. The formulae are compared with primal–dual FEM limit analyses and with burst tests. Even closer predictions are obtained with iterative limit load solutions for the von Mises yield function and for the Tresca yield function. Pressure loading of the faces of interior cracks in thick pipes reduces the collapse load of circumferential defects more than for axial flaws. Axial defects have been treated in part I of the paper.
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.engfracmech.2012.05.017
SN  - 0013-7944
VL  - 97
SP  - 314
EP  - 333
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Trenz, Eva
A1  - Lohmann, Philipp
A1  - Frotscher, Ralf
A1  - Klinge, Uwe
A1  - Tabaza, Ruth
A1  - Kirschner-Hermanns, Ruth
T1  - New measurements to compare soft tissue anchoring systems in pelvic floor surgery
JF  - Journal of Biomedical Materials Research Part B: Applied Biomaterials
N2  - Suburethral slings as well as different meshes are widely used treating stress urinary incontinence and prolaps in women. With the development of MiniSlings and special meshes using less alloplastic material anchorage systems become more important to keep devices in place and to put some tension especially on the MiniSlings. To date, there are many different systems of MiniSlings of different companies on the market which differ in the structure of the used meshes and anchors. A new objective measurement method to compare different properties of MiniSling systems (mesh and anchor) is presented in this article. Ballistic gelatine acts as soft tissue surrogate. Significant differences in parameters like pull-out strength of anchors or shrinkage of meshes under loading conditions have been determined. The form and size of the anchors as well as the structural stability of the meshes are decisive for a proper integration. The tested anchorings sytems showed markedly different mechanical function at their respective load bearing capacity. As the stable fixation of the device in tissue is a prerequisite for a permanet reinforcement, the proposed test system permits further optimisation of anchor and mesh devices to improve the success of the surgical treatment
Y1  - 2012
U6  - http://dx.doi.org/10.1002/jbm.b.32654
SN  - 1552-4981
VL  - 100B
IS  - 4
SP  - 924
EP  - 933
PB  - Wiley
CY  - Hoboken, NJ
ER  - 
TY  - JOUR
A1  - Novacek, V.
A1  - Tran, Thanh Ngoc
A1  - Klinge, U.
A1  - Tolba, R. H.
A1  - Staat, Manfred
A1  - Bronson, D. G.
A1  - Miesse, A. M.
A1  - Whiffen, J.
A1  - Turquier, F.
T1  - Finite element modelling of stapled colorectal end-to-end anastomosis : Advantages of variable height stapler design
JF  - Journal of Biomechanics
N2  - The impact of surgical staplers on tissues has been studied mostly in an empirical manner. In this paper, finite element method was used to clarify the mechanics of tissue stapling and associated phenomena. Various stapling modalities and several designs of circular staplers were investigated to evaluate the impact of the device on tissues and mechanical performance of the end-to-end colorectal anastomosis. Numerical simulations demonstrated that a single row of staples is not adequate to resist leakage due to non-linear buckling and opening of the tissue layers between two adjacent staples. Compared to the single staple row configuration, significant increase in stress experienced by the tissue at the inner staple rows was observed in two and three rows designs. On the other hand, adding second and/or third staple row had no effect on strain in the tissue inside the staples. Variable height design with higher staples in outer rows significantly reduced the stresses and strains in outer rows when compared to the same configuration with flat cartridge.
KW  - Variable height stapler design
KW  - Anastomotic leakage
KW  - Finite element modelling
KW  - End-to-end colorectal anastomosis
KW  - Surgical staplers
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.jbiomech.2012.07.021
SN  - 1873-2380
VL  - 45
IS  - 115
SP  - 2693
EP  - 2697
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Nguyen, Nhu Huynh
A1  - Duong, Minh Tuan
A1  - Tran, Thanh Ngoc
A1  - Pham, Phu Tinh
A1  - Grottke, O.
A1  - Tolba, R.
A1  - Staat, Manfred
T1  - Influence of a freeze–thaw cycle on the stress–stretch curves of tissues of porcine abdominal organs
JF  - Journal of Biomechanics
N2  - The paper investigates both fresh porcine spleen and liver and the possible decomposition of these organs under a freeze–thaw cycle. The effect of tissue preservation condition is an important factor which should be taken into account for protracted biomechanical tests. In this work, tension tests were conducted for a large number of tissue specimens from twenty pigs divided into two groups of 10. Concretely, the first group was tested in fresh state; the other one was tested after a freeze-thaw cycle which simulates the conservation conditions before biomechanical experiments. A modified Fung model for isotropic behavior was adopted for the curve fitting of each kind of tissues. Experimental results show strong effects of the realistic freeze–thaw cycle on the capsule of elastin-rich spleen but negligible effects on the liver which virtually contains no elastin. This different behavior could be explained by the autolysis of elastin by elastolytic enzymes during the warmer period after thawing. Realistic biomechanical properties of elastin-rich organs can only be expected if really fresh tissue is tested. The observations are supported by tests of intestines.
KW  - Autolysis
KW  - Decomposition
KW  - Freeze–thaw process
KW  - Spleen
KW  - Liver
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.jbiomech.2012.07.008
SN  - 1873-2380
VL  - 45
IS  - 14
SP  - 2382
EP  - 2386
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Hasan, Istabrak
A1  - Keil, Ludger
A1  - Staat, Manfred
A1  - Wahl, Gerhard
A1  - Bourauel, Christoph
T1  - Determination of the frictional coefficient of the implant-antler interface : experimental approach
JF  - Biomedical Engineering / Biomedizinische Technik
N2  - The similar bone structure of reindeer antler to human bone permits studying the osseointegration of dental implants in the jawbone. As the friction is one of the major factors that have a significant influence on the initial stability of immediately loaded dental implants, it is essential to define the frictional coefficient of the implant-antler interface. In this study, the kinetic frictional forces at the implant-antler interface were measured experimentally using an optomechanical setup and a stepping motor controller under different axial loads and sliding velocities. The corresponding mean values of the static and kinetic frictional coefficients were within the range of 0.5–0.7 and 0.3–0.5, respectively. An increase in the frictional forces with increasing applied axial loads was registered. The measurements showed an evidence of a decrease in the magnitude of the frictional coefficient with increasing sliding velocity. The results of this study provide a considerable assessment to clarify the suitable frictional coefficient to be used in the finite element contact analysis of antler specimens.
Y1  - 2012
SN  - 1862-278X
VL  - 57
IS  - 5
SP  - 359
EP  - 363
PB  - De Gruyter
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Staat, Manfred
T1  - Limit and shakedown analysis under uncertainty
JF  - Tap chi Khoa hoc & ung dung - Dai hoc Ton Duc Thang
Y1  - 2012
N1  - = Journal of Applied Sciences - Ton Duc Thang University
VL  - 19
SP  - 45
EP  - 47
ER  - 
TY  - JOUR
A1  - Pham, Phu Tinh
A1  - Staat, Manfred
T1  - An Upper Bound Algorithm for Limit and Shakedown Analysis of Bounded Linearly Kinematic Hardening Structures
JF  - Limit State of Materials and Structures : Direct Methods 2. Saxcé, Géry de (Hrsg.)
Y1  - 2013
SN  - 978-94-007-5424-9
SP  - 71
EP  - 87
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Tran, Thanh Ngoc
A1  - Staat, Manfred
T1  - An Edge-Based Smoothed Finite Element Method for Primal-Dual Shakedown Analysis of Structures Under Uncertainties
JF  - Limit State of Materials and Structures : Direct Methods 2. Saxcé, Géry de (Hrsg.)
Y1  - 2013
SN  - 978-94-007-5424-9
SP  - 89
EP  - 102
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Staat, Manfred
T1  - Limit and shakedown analysis under uncertainty
JF  - International journal of computational methods : IJCM
Y1  - 2013
SN  - 0219-8762
SP  - Publ. online
PB  - World Scientific Publishing
CY  - Singapore
ER  - 
TY  - JOUR
A1  - Jung, Alexander
A1  - Staat, Manfred
A1  - Müller, Wolfram
T1  - Flight style optimization in ski jumping on normal, large, and ski flying hills
JF  - Journal of biomechanics
Y1  - 2013
SN  - 1873-2380 (E-Journal); 0021-9290 (Print)
N1  - Corrigendum to “Flight style optimization in ski jumping on normal, large, and ski flying hills” [J. Biomech 47 (2014) 716-722] Journal of Biomechanics, 2018;71:313.
VL  - Vol. 47
IS  - Iss. 3
SP  - 716
EP  - 722
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Anding, Ralf
A1  - Tabaza, Ruth
A1  - Staat, Manfred
A1  - Trenz, Eva
A1  - Lohmann, Philipp
A1  - Klinge, Uwe
A1  - Kirschner-Hermanns, Ruth
T1  - Introducing a method of in vitro testing of different anchoring systems used for female incontinence and prolapse surgery
JF  - BioMed research international
Y1  - 2013
SN  - 1110-7251 (E-Journal); 2314-6141 (E-Journal); 1110-7243 (Print); 2314-6133 (Print)
VL  - Vol. 2013
SP  - Article ID 401417
ER  - 
TY  - JOUR
A1  - Pham, Phu Tinh
A1  - Staat, Manfred
T1  - FEM-based shakedown analysis of hardening structures
JF  - Asia Pacific journal on computational engineering
N2  - This paper develops a new finite element method (FEM)-based upper bound algorithm for limit and shakedown analysis of hardening structures by a direct plasticity method. The hardening model is a simple two-surface model of plasticity with a fixed bounding surface. The initial yield surface can translate inside the bounding surface, and it is bounded by one of the two equivalent conditions: (1) it always stays inside the bounding surface or (2) its centre cannot move outside the back-stress surface. The algorithm gives an effective tool to analyze the problems with a very high number of degree of freedom. Our numerical results are very close to the analytical solutions and numerical solutions in literature.
Y1  - 2014
U6  - http://dx.doi.org/10.1186/2196-1166-1-4
SN  - 2196-1166 (E-Journal)
IS  - 1
SP  - Article No. 4
PB  - SpringerOpen
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Frotscher, Ralf
A1  - Staat, Manfred
T1  - Stresses produced by different textile mesh implants in a tissue equivalent
JF  - BioNanoMaterials
N2  - Two single-incision mini-slings used for treating urinary incontinence in women are compared with respect to the stresses they produce in their surrounding tissue. In an earlier paper we experimentally observed that these implants produce considerably different stress distributions in a muscle tissue equivalent. Here we perform 2D finite element analyses to compare the shear stresses and normal stresses in the tissue equivalent for the two meshes and to investigate their failure behavior. The results clearly show that the Gynecare TVT fails for increasing loads in a zipper-like manner because it gradually debonds from the surrounding tissue. Contrary to that, the tissue at the ends of the DynaMesh-SIS direct may rupture but only at higher loads. The simulation results are in good agreement with the experimental observations thus the computational model helps to interpret the experimental results and provides a tool for qualitative evaluation of mesh implants.
Y1  - 2014
U6  - http://dx.doi.org/10.1515/bnm-2014-0003
SN  - 2191-4672 (E-Journal); 2193-066X (E-Journal); 0011-8656 (Print); 1616-0177 (Print); 2193-0651 (Print)
VL  - 15
IS  - 1-2
SP  - 25
EP  - 30
PB  - De Gruyter
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Frotscher, Ralf
A1  - Koch, Jan-Peter
A1  - Staat, Manfred
T1  - Computational investigation of drug action on human-induced stem cell derived cardiomyocytes
JF  - Journal of biomechanical engineering
Y1  - 2015
U6  - http://dx.doi.org/10.1115/1.4030173
SN  - 1528-8951 (E-Journal); 0148-0731 (Print)
VL  - Vol. 137
IS  - iss. 7
SP  - 071002-1
EP  - 071002-7
PB  - ASME
CY  - New York
ER  - 
TY  - JOUR
A1  - Duong, Minh Tuan
A1  - Nguyen, Nhu Huynh
A1  - Tran, Thanh Ngoc
A1  - Tolba, R. H.
A1  - Staat, Manfred
T1  - Influence of refrigerated storage on tensile mechanical properties of porcine liver and spleen
JF  - International biomechanics
Y1  - 2015
U6  - http://dx.doi.org/10.1080/23335432.2015.1049295
SN  - 2333-5432
VL  - Vol. 2
IS  - Iss. 1
SP  - 79
EP  - 88
PB  - Taylor & Francis
CY  - London
ER  - 
TY  - JOUR
A1  - Duong, Minh Tuan
A1  - Nguyen, Nhu Huynh
A1  - Staat, Manfred
T1  - Physical response of hyperelastic models for composite materials and soft tissues
JF  - Asia pacific journal on computational engineering
Y1  - 2015
U6  - http://dx.doi.org/10.1186/s40540-015-0015-x
SN  - 2196-1166
VL  - 2
IS  - 3 (December 2015)
SP  - 1
EP  - 18
ER  - 
TY  - JOUR
A1  - Goßmann, Matthias
A1  - Frotscher, Ralf
A1  - Linder, Peter
A1  - Bayer, Robin
A1  - Epple, U.
A1  - Staat, Manfred
A1  - Temiz Artmann, Aysegül
A1  - Artmann, Gerhard
T1  - Mechano-pharmacological characterization of cardiomyocytes derived from human induced pluripotent stem cells
JF  - Cellular physiology and biochemistry
N2  - Background/Aims: Common systems for the quantification of cellular contraction rely on animal-based models, complex experimental setups or indirect approaches. The herein presented CellDrum technology for testing mechanical tension of cellular monolayers and thin tissue constructs has the potential to scale-up mechanical testing towards medium-throughput analyses. Using hiPS-Cardiac Myocytes (hiPS-CMs) it represents a new perspective of drug testing and brings us closer to personalized drug medication. Methods: In the present study, monolayers of self-beating hiPS-CMs were grown on ultra-thin circular silicone membranes and deflect under the weight of the culture medium. Rhythmic contractions of the hiPS-CMs induced variations of the membrane deflection. The recorded contraction-relaxation-cycles were analyzed with respect to their amplitudes, durations, time integrals and frequencies. Besides unstimulated force and tensile stress, we investigated the effects of agonists and antagonists acting on Ca²⁺ channels (S-Bay K8644/verapamil) and Na⁺ channels (veratridine/lidocaine). Results: The measured data and simulations for pharmacologically unstimulated contraction resembled findings in native human heart tissue, while the pharmacological dose-response curves were highly accurate and consistent with reference data. Conclusion: We conclude that the combination of the CellDrum with hiPS-CMs offers a fast, facile and precise system for pharmacological, toxicological studies and offers new preclinical basic research potential.
KW  - Inotropic compounds
KW  - Pharmacology
KW  - Ion channels
KW  - CellDrum
KW  - Heart tissue culture
KW  - Induced pluripotent stem cells
KW  - Cardiac myocytes
Y1  - 2016
U6  - http://dx.doi.org/10.1159/000443124
SN  - 1421-9778 (Online)
SN  - 1015-8987 (Print)
VL  - 38
IS  - 3
SP  - 1182
EP  - 1198
PB  - Karger
CY  - Basel
ER  - 
TY  - JOUR
A1  - Frotscher, Ralf
A1  - Muanghong, Danita
A1  - Dursun, Gözde
A1  - Goßmann, Matthias
A1  - Temiz Artmann, Aysegül
A1  - Staat, Manfred
T1  - Sample-specific adaption of an improved electro-mechanical model of in vitro cardiac tissue
JF  - Journal of Biomechanics
N2  - We present an electromechanically coupled computational model for the investigation of a thin cardiac tissue construct consisting of human-induced pluripotent stem cell-derived atrial, ventricular and sinoatrial cardiomyocytes. The mechanical and electrophysiological parts of the finite element model, as well as their coupling are explained in detail. The model is implemented in the open source finite element code Code_Aster and is employed for the simulation of a thin circular membrane deflected by a monolayer of autonomously beating, circular, thin cardiac tissue. Two cardio-active drugs, S-Bay K8644 and veratridine, are applied in experiments and simulations and are investigated with respect to their chronotropic effects on the tissue. These results demonstrate the potential of coupled micro- and macroscopic electromechanical models of cardiac tissue to be adapted to experimental results at the cellular level. Further model improvements are discussed taking into account experimentally measurable quantities that can easily be extracted from the obtained experimental results. The goal is to estimate the potential to adapt the presented model to sample specific cell cultures.
KW  - hiPS cardiomyocytes
KW  - Homogenization
KW  - Hodgkin–Huxley models
KW  - Frequency adaption
KW  - Electromechanical modeling
KW  - Drug simulation
KW  - Computational biomechanics
KW  - Cardiac tissue
Y1  - 2016
U6  - http://dx.doi.org/10.1016/j.jbiomech.2016.01.039
SN  - 0021-9290 (Print)
SN  - 1873-2380 (Online)
VL  - 49
IS  - 12
SP  - 2428
EP  - 2435
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Hackl, Michael
A1  - Müller, Lars-Peter
A1  - Staat, Manfred
A1  - Kahmann, Stephanie Lucina
A1  - Wegmann, Kilian
T1  - Proximal phalangeal neck fractures of the hand — a biomechanical comparison of three fixation techniques
JF  - Knee surgery, sports traumatology, arthroscopy
N2  - Plate osteosynthesis of displaced proximal phalangeal neck fractures of the hand allows early mobilization due to a stable internal fixation. Nevertheless, joint stiffness—because of soft tissue irritation—represents a common complication leading to high complication rates. Del Pinal et al. recently reported promising clinical results for a new, minimally invasive fixation technique with a cannulated headless intramedullary compression screw. Hence, the aim of this study was to compare plate fixation of proximal phalangeal neck fractures to less two less invasive techniques: Crossed k-wire fixation and intramedullary screw fixation. We hypothesized that these fixation techniques provide inferior stability when compared to plate osteosynthesis.
Y1  - 2016
U6  - http://dx.doi.org/10.1007/s00167-016-4080-7
SN  - 0942-2056
VL  - Volume 24
IS  - Supplement 1
SP  - 148
EP  - 149
PB  - Springer
CY  - Berlin
ER  -