Non-Probabilistic Reliability Bounds Method for Series Structural Systems Considering Redundant Failure Modes

Non-probabilistic structural reliability analysis is based on the convex model and more applicable for practical engineering problems with limited samples. Recently, the authors proposed a non-probabilistic reliability bounds method (NRBM) for series structural systems as an effective means for the assessment of systems' non-probabilistic reliability. A novel non-probabilistic reliability bounds method considering redundant failure modes is proposed in this paper for series structural systems to further improve the efficiency and accuracy of the NRBM. By decomposing the system into several subsystems with two or three failure modes, three identification criteria for redundant failure modes are developed for these subsystems. A bounding formula for the system's non-probabilistic failure degree is then derived after removing the redundant failure modes. An investigation of three numerical examples indicates that the proposed method has a higher efficiency and at least equivalent accuracy compared to the NRBM.