SYSTEM RELIABILITY ASSESSMENT OF REDUNDANT TRUSSES USING IMPROVED ALGEBRAIC FORCE METHOD AND ARTIFICIAL INTELLIGENCE

Calculation of system failure probability in large redundant structures is a time consuming process. Therefore in many researches it has been approximated in a conservative manner directly from probability of the failure of the members. This paper proposes three strategies to speed up the calculation of Pf of indeterminate trusses. In the first strategy based on the principles of probability, a criterion is established to discard some correlated paths. In the second strategy the force method is developed and applied due to its efficiency and speed in analyzing large redundant trusses. In the force method, the number of equations to be solved is the same as the degree of static indeterminacy which is usually smaller than the total degree of freedom used in conventional displacement method. Another advantage of the force method is the immediate access to member forces, which is required to be used in reliability analysis. In this research the force method formulation is improved and made it possible for the analysis of trusses of different topologies. The third strategy corresponds to employing an Artificial Intelligent agent to identify and control the repeated failure paths to avoid the use of extra computational time.