Fuzzy Finite Element Method Of Fuzzy Reliability Analysis Of Structures

The uncertain factors affecting reliability of structures include not only stochastic uncertainty but also fuzzy one. However the traditional reliability theory neglect the fuzzy factors in structures. This dissertation established numerical methods in the fuzzy structural analysis on the basis of fuzzy variational principle and peak fuzzy number. The numerical methods of fuzzy analysis for thin-walled box girders are studied systematically, the one-dimensional fuzzy finite element method for thin-walled box girders is proposed. The fuzzy reliability of thin-walled box girders is studied, providing us more valuable information for reliability analysis of structures with fuzzy factors.The main contributions of the thesis are as follows:1.Combining the method for reliability analysis based on stochastic finite element method with peak fuzzy number's operations, the method for fuzzy-random reliability analysis of structures is established.2.By means of fuzzy finite element method, the method for fuzzy reliability analysis of structures are put forward based on possibility theory.3.Fuzzy vibration finite element method is established, which is used in vibration analysis of fuzzy beam.4.Combining fuzzy variational principle with the theory of thin-walled box girders, the one-dimensional fuzzy finite element method for thin-walled box girders is proposed.5. Combining the method for fuzzy reliability analysis of structures based on possibility theory with the one-dimensional fuzzy finite element method for thin-walled box girders, the method for reliability analysis of thin-walled box girders are put forward based on fuzzy finite element method.