Recent studies in medicine, economics and engineering have demonstrated that fuzzy set theory may indeed by a useful tool for the expression of professional judgement. Studies in structural engineering have been on damage assessment due to fatigue, and seismic loads. This research will emphasize the reliability and safety of existing (including newly constructed) plane frame structures. Classical reliability analysis will be used first to calculate the structure's reliability measure using objective information such as yield strength of materials, geometry of structures and applied loads. The reliability measure will then be updated utilizing the fuzzy set logic to include the quality of connections and structural members through inspections. Other parameters pertinent to the overall safety of a structure will also be investigated. An algorithm for updating the objective reliability will be presented. The significance of incorporating the subjective information in reliability analyses will be discussed. The results of this proposed study are expected to provide a more precise assessment on the safety of structures. These results are expected to enhance the engineers or owners' decision-making process in determining appropriate action to the structure such as maintenance, and rehabilitation, etc.
