Study On Fuzzy Random Reliability Of Existed Civil Buildings And Appraisal Program Designing

Not only random uncertainty of the variables but also fuzzy one is included in the uncertain factors that affect the reliability of structures. However, the fuzzy factors can't be solved by the traditonal reliability theroy. In order to solve this problem, how to apply fuzzy theory to reliability appraisal of civil buildings and reliability theory of structures is mainly discussed in the dissertation.Firstly, traditional reliability of structures is simply introduced in the dissertation, all kinds of uncertain factors affecting the reliability of structures are analyzed, then the development of reliability of structures and reliability appraisal of civil buildings are reviewed, the actual research condition of fuzzy random reliability of structures is analyzed; Secondly, the reliability appraisal theory is studied in the dissertation, the appraisal model and fuzzy analytic hierarchy process(FAHP) are simply introduced, then the steps of fuzzy comprehensive evaluation method and classification of the grade of civil buildings by asymmetric approach degree method are presented; Thirdly, fuzzy random reliability of structures is studied in the dissertation, the basic knowledge of fuzzy theory is simply introduced and fuzzy random variable is defined, the structural fuzzy random limit state equation is established according to the analysis of fuzziness between safety state and failure state, a structural fuzzy safety criterion of single failure mode is given, structural fuzzy random failure probability, fuzzy random reliability and fuzzy random reliability index are discussed underα-constraint level, then three practical calculation methods of fuzzy random reliability indexβ~ are put forward.As a part of serial programs, the reliability appraisal program of steel structure surrounding system is designed for practical structural use, mainly according to(GB50292-1999), the introduction of software language and surrounding system, the work of software development, and the display of some software interfaces are included.The analytic results of this paper are presented as follow: it is more impersonal to apply fuzzy theory to reliability appraisal; it is feasible to substitute fuzzy random reliability for traditional random reliability, it is more reasonable to substitute the interval value of fuzzy random reliability index for certain value.Finally, the suggestions to some concerned problems needing to be studied...