TY  - CHAP
A1  - Tran, Thanh Ngoc
A1  - Staat, Manfred
A1  - Kreißig, R.
T1  - Calculation of load carrying capacity of shell structures with elasto-plastic material by direct methods
N2  - Proceedings of the International Conference on Material Theory and Nonlinear Dynamics. MatDyn. Hanoi, Vietnam, Sept. 24-26, 2007, 8 p. In this paper, a method is introduced to determine the limit load of general shells using the finite element method. The method is based on an upper bound limit and shakedown analysis with elastic-perfectly plastic material model. A non-linear constrained optimisation problem is solved by using Newton’s method in conjunction with a penalty method and the Lagrangean dual method. Numerical investigation of a pipe bend subjected to bending moments proves the effectiveness of the algorithm.
KW  - Finite-Elemente-Methode
Y1  - 2007
ER  - 
TY  - CHAP
A1  - Tran, Thanh Ngoc
A1  - Staat, Manfred
A1  - Kreißig, R.
T1  - Finite element shakedown and limit reliability analysis of thin shells
N2  - A procedure for the evaluation of the failure probability of elastic-plastic thin shell structures is presented. The procedure involves a deterministic limit and shakedown analysis for each probabilistic iteration which is based on the kinematical approach and the use the exact Ilyushin yield surface. Based on a direct definition of the limit state function, the non-linear problems may be efficiently solved by using the First and Second Order Reliabiblity Methods (Form/SORM). This direct approach reduces considerably the necessary knowledge of uncertain technological input data, computing costs and the numerical error. In: Computational plasticity / ed. by Eugenio Onate. Dordrecht: Springer 2007. VII, 265 S. (Computational Methods in Applied Sciences ; 7) (COMPLAS IX. Part 1 . International Center for Numerical Methods in Engineering (CIMNE)). ISBN 978-1-402-06576-7  S. 186-189
KW  - Finite-Elemente-Methode
KW  - Limit analysis
KW  - shakedown analysis
KW  - Exact Ilyushin yield surface
KW  - Random variable
KW  - First Order Reliabiblity Method
Y1  - 2007
ER  - 
TY  - CHAP
A1  - Staat, Manfred
T1  - Problems and chances for probabilistic fracture mechanics in the analysis of steel pressure boundary reliability. - Überarb. Ausg.
N2  - In: Technical feasibility and reliability of passive safety systems for nuclear power plants. Proceedings of an Advisory Group Meeting held in Jülich, 21-24 November 1994. - Vienna , 1996. - Seite: 43 - 55 IAEA-TECDOC-920 Abstract: It is shown that the difficulty for probabilistic fracture mechanics (PFM) is the general problem of the high reliability of a small population. There is no way around the problem as yet. Therefore what PFM can contribute to the reliability of steel pressure boundaries is demon­strated with the example of a typical reactor pressure vessel and critically discussed. Although no method is distinguishable that could give exact failure probabilities, PFM has several addi­tional chances. Upper limits for failure probability may be obtained together with trends for design and operating conditions. Further, PFM can identify the most sensitive parameters, improved control of which would increase reliability. Thus PFM should play a vital role in the analysis of steel pressure boundaries despite all shortcomings.
KW  - Bruchmechanik
KW  - probabilistic fracture mechanics
KW  - PFM
Y1  - 2006
ER  -