TY  - JOUR
A1  - Topçu, Murat
A1  - Madabhushi, Gopal S.P.
A1  - Staat, Manfred
T1  - A generalized shear-lag theory for elastic stress transfer between matrix and fibres having a variable radius
JF  - International Journal of Solids and Structures
N2  - 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.
KW  - Natural fibres
KW  - Polymer-matrix composites
KW  - Biocomposites
KW  - Stress concentrations
KW  - Finite element analysis
Y1  - 2022
U6  - http://dx.doi.org/10.1016/j.ijsolstr.2022.111464
SN  - 0020-7683
VL  - 239–240
IS  - Art. No. 111464
PB  - Elsevier
CY  - New York, NY
ER  - 
TY  - CHAP
A1  - Tran, N. T.
A1  - Tran, Thanh Ngoc
A1  - Matthies, M. G.
A1  - Stavroulakis, G. E.
A1  - Staat, Manfred
T1  - Shakedown Analysis Under Stochastic Uncertainty by Chance Constrained Programming
T2  - Advances in Direct Methods for Materials and Structures
N2  - In this paper we propose a stochastic programming method to analyse limit and shakedown of structures under uncertainty condition of strength. Based on the duality theory, the shakedown load multiplier formulated by the kinematic theorem is proved actually to be the dual form of the shakedown load multiplier formulated by static theorem. 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 and the shakedown limit. The edge-based smoothed finite element method (ES-FEM) with three-node linear triangular elements is used for structural analysis.
Y1  - 2017
SN  - 978-3-319-59810-9
U6  - http://dx.doi.org/10.1007/978-3-319-59810-9_6
SP  - 85
EP  - 103
PB  - Springer
CY  - Cham
ER  - 
TY  - CHAP
A1  - Tran, Ngoc Trinh
A1  - Matthies, Hermann G.
A1  - Stavroulakis, Georgios Eleftherios
A1  - Staat, Manfred
T1  - Direct plastic structural design by chance constrained programming
T2  - 6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK
N2  - 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.
Y1  - 2018
ER  - 
TY  - JOUR
A1  - Tran, Ngoc Trinh
A1  - Staat, Manfred
T1  - Direct plastic structural design under lognormally distributed strength by chance constrained programming
JF  - Optimization and Engineering
N2  - We propose the so-called chance constrained programming model of stochastic programming theory to analyze limit and shakedown loads of structures under random strength with a lognormal distribution. A dual chance constrained programming algorithm is developed to calculate simultaneously both the upper and lower bounds of the plastic collapse limit and the shakedown limit. The edge-based smoothed finite element method (ES-FEM) is used with three-node linear triangular elements.
Y1  - 2020
U6  - http://dx.doi.org/10.1007/s11081-019-09437-2
SN  - 1573-2924
VL  - 21
IS  - 1
SP  - 131
EP  - 157
PB  - Springer Nature
CY  - Cham
ER  - 
TY  - JOUR
A1  - Tran, Ngoc Trinh
A1  - Staat, Manfred
T1  - Direct plastic structural design under random strength and random load by chance constrained programming
JF  - European Journal of Mechanics - A/Solids
Y1  - 2021
U6  - http://dx.doi.org/10.1016/j.euromechsol.2020.104106
SN  - 0997-7538
VL  - 85
IS  - Article 104106
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Tran, Ngoc Trinh
A1  - Staat, Manfred
T1  - FEM shakedown analysis of Kirchhoff-Love plates under uncertainty of strength
T2  - Proceedings of UNCECOMP 2021
N2  - A new formulation to calculate the shakedown limit load of Kirchhoff plates under stochastic conditions of strength is developed. Direct structural reliability design by chance con-strained programming is based on the prescribed failure probabilities, which is an effective approach of stochastic programming if it can be formulated as an equivalent deterministic optimization problem. We restrict uncertainty to strength, the loading is still deterministic. A new formulation is derived in case of random strength with lognormal distribution. Upper bound and lower bound shakedown load factors are calculated simultaneously by a dual algorithm.
Y1  - 2021
SN  - 978-618-85072-6-5
U6  - http://dx.doi.org/10.7712/120221.8041.19047
N1  - Proceedings of UNCECOMP 2021, 4th International Conference on Uncertainty Quantification in Computational Sciences and Engineering, streamed from Athens, Greece, 28–30 June 2021.
SP  - 323
EP  - 338
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  - CHAP
A1  - Tran, Ngoc Trinh
A1  - Tran, Thanh Ngoc
A1  - Matthies, H. G.
A1  - Stavroulakis, G. E.
A1  - Staat, Manfred
ED  - Papadrakakis, M.
T1  - Shakedown analysis of plate bending analysis under stochastic uncertainty by chance constrained programming
T2  - ECCOMAS Congress 2016, VII European Congress on Computational Methods in Applied Sciences and Engineering. Crete Island, Greece, 5–10 June 2016
Y1  - 2016
ER  - 
TY  - CHAP
A1  - Tran, Ngoc Trinh
A1  - Tran, Thanh Ngoc
A1  - Matthies, Hermann G.
A1  - Stavroulakis, Georgios Eleftherios
A1  - Staat, Manfred
T1  - FEM Shakedown of uncertain structures by chance constrained programming
T2  - PAMM Proceedings in Applied Mathematics and Mechanics
Y1  - 2016
U6  - http://dx.doi.org/10.1002/pamm.201610346
SN  - 1617-7061
N1  - Special Issue:
Joint 87th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM) and Deutsche Mathematiker-Vereinigung
VL  - 16
IS  - 1
SP  - 715
EP  - 716
ER  - 
TY  - CHAP
A1  - Tran, Ngoc Trinh
A1  - Trinh, Tu Luc
A1  - Dao, Ngoc Tien
A1  - Giap, Van Tan
A1  - Truong, Manh Khuyen
A1  - Dinh, Thuy Ha
A1  - Staat, Manfred
T1  - Limit and shakedown analysis of structures under random strength
T2  - Proceedings of (NACOME2022) The 11th National Conference on Mechanics, Vol. 1. Solid Mechanics, Rock Mechanics, Artificial Intelligence, Teaching and Training, Hanoi, December 2-3, 2022
N2  - Direct methods comprising limit and shakedown analysis is a branch of computational mechanics. It plays a significant role in mechanical and civil engineering design. The concept of direct method aims to determinate the ultimate load bearing capacity of structures beyond the elastic range. For practical problems, the direct methods lead to nonlinear convex optimization problems with a large number of variables and onstraints. If strength and loading are random quantities, the problem of shakedown analysis is considered as stochastic programming. This paper presents a method so called chance constrained programming, an effective method of stochastic programming, to solve shakedown analysis problem under random condition of strength. In this our investigation, the loading is deterministic, the strength is distributed as normal or lognormal variables.
KW  - Reliability of structures
KW  - Stochastic programming
KW  - Chance constrained programming
KW  - Shakedown analysis
KW  - Limit analysis
Y1  - 2022
SN  - 978-604-357-084-7
SP  - 510
EP  - 518
PB  - Nha xuat ban Khoa hoc tu nhien va Cong nghe (Verlag Naturwissenschaft und Technik)
CY  - Hanoi
ER  - 
TY  - JOUR
A1  - Tran, Ngoc Trinh
A1  - Trinh, Tu Luc
A1  - Dao, Ngoc Tien
A1  - Giap, Van Tan
A1  - Truong, Manh Khuyen
A1  - Dinh, Thuy Ha
A1  - Staat, Manfred
T1  - FEM shakedown analysis of structures under random strength with chance constrained programming
JF  - Vietnam Journal of Mechanics
N2  - Direct methods, comprising limit and shakedown analysis, are a branch of computational mechanics. They play a significant role in mechanical and civil engineering design. The concept of direct methods aims to determine the ultimate load carrying capacity of structures beyond the elastic range. In practical problems, the direct methods lead to nonlinear convex optimization problems with a large number of variables and constraints. If strength and loading are random quantities, the shakedown analysis can be formulated as stochastic programming problem. In this paper, a method called chance constrained programming is presented, which is an effective method of stochastic programming to solve shakedown analysis problems under random conditions of strength. In this study, the loading is deterministic, and the strength is a normally or lognormally distributed variable.
KW  - limit analysis
KW  - shakedown analysis
KW  - chance constrained programming
KW  - stochastic programming
KW  - reliability of structures
Y1  - 2022
U6  - http://dx.doi.org/10.15625/0866-7136/17943
SN  - 0866-7136
SN  - 2815-5882
VL  - 44
IS  - 4
SP  - 459
EP  - 473
PB  - Vietnam Academy of Science and Technology (VAST)
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  - 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  - CHAP
A1  - Tran, Thanh Ngoc
A1  - Novacek, V.
A1  - Tolba, R.
A1  - Klinge, U.
A1  - Turquier, F.
A1  - Staat, Manfred
T1  - 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
N2  - 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.
KW  - Anastomose
KW  - Finite-Elemente-Methode
KW  - Biomechanik
KW  - Anastomosis
KW  - Finite element method
KW  - Biomechanics
Y1  - 2011
ER  - 
TY  - CHAP
A1  - Tran, Thanh Ngoc
A1  - Pham, Phu Tinh
A1  - Staat, Manfred
T1  - Reliability analysis of shells based on direct plasticity methods
N2  - 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
N2  - Abstracts of the Proceedings of the 8th World Congress on Computational Mechanics (WCCM8) and 5th Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2008) June 30th - July, 4th 2008, Venice, Italy. 2 pages with abstracts of the authors, Ill. and references.
KW  - Finite-Elemente-Methode
KW  - Limit analysis
KW  - Shakedown analysis
KW  - First-order reliability method
KW  - second-order reliability method
KW  - Sensitivity
Y1  - 2008
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  - 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  - 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  - CHAP
A1  - Tran, Thanh Ngoc
A1  - Staat, Manfred
ED  - Eberhardsteiner, J.
T1  - A primal-dual shakedown analysis of 3D structures using the face-based smoothed finite element method
T2  - Proceedings European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012)
Y1  - 2012
N1  - 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012
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  - http://dx.doi.org/10.1007/978-94-007-6827-7_5
SP  - 101
EP  - 117
PB  - Springer
CY  - Dordrecht [u.a.]
ER  -