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  - 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  - 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  - https://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  - 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  - https://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  - https://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  - 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  - 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  - CHAP
A1  - Tran, Thanh Ngoc
A1  - Staat, Manfred
T1  - Shakedown analysis of Reissner-Mindlin plates using the edge-based smoothed finite element method
T2  - Direct methods for limit states in structures and materials / Dieter Weichert ; Alan Ponter, ed.
N2  - 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.
Y1  - 2014
SN  - 978-94-007-6826-0 (Print) 978-94-007-6827-7 (Online)
U6  - https://doi.org/10.1007/978-94-007-6827-7_5
SP  - 101
EP  - 117
PB  - Springer
CY  - Dordrecht [u.a.]
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  - 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  - https://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  - CHAP
A1  - Frotscher, Ralf
A1  - Koch, Jan-Peter
A1  - Raatschen, Hans-Jürgen
A1  - Staat, Manfred
ED  - Onate, E.
T1  - Evaluation of a computational model for drug action on cardiac tissue
T2  - 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
Y1  - 2014
SP  - 1
EP  - 12
ER  - 
TY  - CHAP
A1  - Jung, Alexander
A1  - Staat, Manfred
A1  - Müller, Wolfram
ED  - Onate, E.
T1  - Optimization of the flight style in ski jumping
T2  - 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
Y1  - 2014
N1  - Das Paper wurde nach der Konferenz überarbeitet.
SP  - 799
EP  - 810
ER  - 
TY  - CHAP
A1  - Bhattarai, Aroj
A1  - Frotscher, Ralf
A1  - Sora, M.-C.
A1  - Staat, Manfred
ED  - Onate, E.
T1  - A 3D finite element model of the female pelvic floor for the reconstruction of urinary incontinence
T2  - 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
Y1  - 2014
SP  - 1
EP  - 12
ER  - 
TY  - CHAP
A1  - Tran, Thanh Ngoc
A1  - Staat, Manfred
ED  - Onate, E.
T1  - Uncertain multimode failure and limit analysis of shells
T2  - 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
Y1  - 2014
SP  - 1
EP  - 12
ER  - 
TY  - CHAP
A1  - Duong, Minh Tuan
A1  - Staat, Manfred
ED  - Onate, E.
T1  - A face-based smoothed finite element method for hyperelastic models and tissue growth
T2  - 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
Y1  - 2014
SP  - 1
EP  - 12
ER  - 
TY  - CHAP
A1  - Tran, Ngoc Trinh
A1  - Staat, Manfred
A1  - Stavroulakis, G. E.
ED  - Onate, E.
T1  - A multicriteria method for truss optimization
T2  - 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
Y1  - 2014
SP  - 1
EP  - 12
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  - CHAP
A1  - Frotscher, Ralf
A1  - Duong, Minh Tuan
A1  - Staat, Manfred
T1  - Simulating beating cardiomyocytes with electromechanical coupling
T2  - II. International Conference on Biomedical Technology : 28-30 October 2015 Hannover, Germany / T. Lenarz, P. Wriggers (Eds.)
Y1  - 2015
SP  - 1
EP  - 2
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  - https://doi.org/10.1186/s40540-015-0015-x
SN  - 2196-1166
VL  - 2
IS  - 3 (December 2015)
SP  - 1
EP  - 18
ER  -