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Application of fuzzy sets to transient analysis of space structures. (English) Zbl 0922.73070

Summary: An application of fuzzy sets, in conjunction with finite elements, to the transient analysis of a precision-deployable space structure is presented. The structural members are modeled by using beam finite elements, and the structure’s latch joint is modeled by using a spring-damper-Coulomb friction element. Two types of transient response simulations are performed: slow transient load–deflection response and transient impulse response. The first simulation is used to evaluate the stiffness and buckling loads at the structure’s tip. The second simulation is used to evaluate the structure’s natural frequencies, mode shapes and the precision of the final shape. For each simulation the possibility distributions of various response quantities are obtained. Fuzzy sets are used to represent three beam properties, namely: damping coefficient, bending stiffness, and axial stiffness, as well as two joint parameters: Coulomb friction force and damping coefficient. Fuzzy set techniques provide an insight into the range of possible responses associated with the combined selected variations in the system parameters.

MSC:

74S05 Finite element methods applied to problems in solid mechanics
74H45 Vibrations in dynamical problems in solid mechanics
03E72 Theory of fuzzy sets, etc.
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