JUDGEMENT TENDENCY AND FUZZY INFERENCE MODEL RELATED TO REDUNDANCY OF FRAMED STRUCTURES AGAINST DISSAPEARANCE OF MEMBER

In these days, some examples have been reported about the collapse of buildings structures by gravity as an outcome resulted from an accidental action or the excitation not prepared in the design process. A redundancy and a key-element has been taken from a viewpoint of assuring robustness of a structure even if it receives unexpected disturbance. In past study, a questionnaire survey for human judgments related to structural redundancy was done. From the results, an assessment method related to redundancy was proposed considering sensitivity and the number of plastic hinges. Also, a “2nd Limit Analysis” method combining the plastic analysis and deformation calculation has been proposed for the occurrence of the mechanical mechanism. In this study, a questionnaire investigation was performed to experts and non-experts about human judgments related to a structural redundancy of framed structures against disappearance of member. From the results, the judgment tendency presents the consideration of combination for the sensitivity index and collapse mode. By abstracting the rules of fuzzy inference about the classification of structural redundancy, the membership function was composed related to human judgement. Furthermore, the method of the determination of the key-element is proposed by reference of the proposed fuzzy inference model.