TY - JOUR
A1 - Staat, Manfred
T1 - Direct FEM Limit and Shakedown Analysis with Uncertain Data
N2 - The structural reliability with respect to plastic collapse or to inadaptation is formulated on the basis of the lower bound limit and shakedown theorems. A direct definition of the limit state function is achieved which permits the use of the highly effective first order reliability methods (FORM) is achieved. The theorems are implemented into a general purpose FEM program in a way capable of large-scale analysis. The limit state function and its gradient are obtained from a mathematical optimization problem. This direct approach reduces considerably the necessary knowledge of uncertain technological input data, the computing time, and the numerical error, leading to highly effective and precise reliability analyses.
KW - Finite-Elemente-Methode
KW - Einspielen
KW - FEM
KW - Einspielanalyse
KW - shakedown
KW - limit load
KW - reliability analysis
KW - FEM
KW - direct method
Y1 - 2000
ER -
TY - JOUR
A1 - Staat, Manfred
T1 - Basis Reduction for the Shakedown Problem for Bounded Kinematic Hardening Material
N2 - Limit and shakedown analysis are effective methods for assessing the load carrying capacity of a given structure. The elasto–plastic behavior of the structure subjected to loads varying in a given load domain is characterized by the shakedown load factor, defined as the maximum factor which satisfies the sufficient conditions stated in the corresponding static shakedown theorem. The finite element dicretization of the problem may lead to very large convex optimization. For the effective solution a basis reduction method has been developed that makes use of the special problem structure for perfectly plastic material. The paper proposes a modified basis reduction method for direct application to the two-surface plasticity model of bounded kinematic hardening material. The considered numerical examples show an enlargement of the load carrying capacity due to bounded hardening.
KW - Finite-Elemente-Methode
KW - Einspielen
KW - Basis Reduktion
KW - konvexe Optimierung
KW - FEM
KW - Druckgeräte
KW - Basis reduction
KW - Convex optimization
KW - FEM
KW - Shakedown analysis
Y1 - 2000
ER -