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  - 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  - 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  - 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  - 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  - 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  - 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  - 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  - GEN
A1  - Topcu, Murat
A1  - Madabhushi, Gopal Santana Phani
A1  - Staat, Manfred
T1  - Datasets from FEM Simulations done with COMSOL Multiphysics and Code_Aster
N2  - Datasets from FEM Simulations done with COMSOL Multiphysics and Code_Aster for an elastic stress transfer between matrix and fibres having a variable radius.
KW  - Natural fibres
KW  - Polymer-matrix composites
KW  - Biocomposites
KW  - Stress concentrations
KW  - Finite element analysis (FEA)
Y1  - 2022
U6  - http://dx.doi.org/10.6084/m9.figshare.19333295.v2
ER  - 
TY  - RPRT
A1  - Stölzle-Feix, Sonja
A1  - Thomas, Ulrich
A1  - Engelstädter, Max
A1  - Goßmann, Matthias
A1  - Linder, Peter
A1  - Staat, Manfred
A1  - Raman, Aravind Hariharan
A1  - Jung, Alexander
A1  - Fertig, Niels
T1  - Plattformtechnologie für kardiale Sicherheitspharmakologie basierend auf teilsynthetischem Herzmuskelgewebe (FLEXcyte) : gemeinsamer FuE-Abschlussbericht aller Partner des Verbundprojektes : Projektlaufzeit: 01.10.2018 bis 30.09.2020
Y1  - 2021
U6  - http://dx.doi.org/10.2314/KXP:1813208581
N1  - Förderkennzeichen BMBF 02P18K020-021
Verbundnummer 01185221
PB  - Nanion Technologies GmbH
CY  - München
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Wolters, J
A1  - Bongarts, W.
A1  - Hennings, W. (u.a.)
T1  - Überarbeitete probabilistisch orientierte Sicherheitsanalyse für den HTR-Modul
JF  - Jahrestagung Kerntechnik '90 / Kerntechnische Gesellschaft e.V. ; Deutsches Atomforum e.V
Y1  - 1990
SP  - 143
EP  - 146
PB  - INFORUM
CY  - Bonn
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  - 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
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  - 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  - CHAP
A1  - Staat, Manfred
A1  - Tran, Thanh Ngoc
A1  - Pham, Phu Tinh
T1  - Limit and shakedown reliability analysis by nonlinear programming
N2  - 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.
KW  - Finite-Elemente-Methode
KW  - Limit analysis
KW  - Shakedown analysis
Y1  - 2008
ER  -