Probabilistic interval limit analysis for structures with hybrid uncertainty

• Hybrid probabilistic interval limit analysis is introduced.
• Valid method is proposed to assess engineering structural safety against collapse.
• Structural reliability bound against collapse failure can be accomplished.
• Both random and interval uncertainties can be simultaneously incorporated.

In this study, the hybrid probabilistic interval limit analysis is introduced to assess the safety of engineering structures against plastic collapse. The presented hybrid uncertainty analysis framework can flexibly model different types of uncertain variables basing on the primitive information of uncertain system parameters. A hybrid probabilistic and interval computational scheme, namely the unified interval stochastic sampling (UISS) approach, is proposed to determine the statistical characteristics (i.e., mean and standard deviation) of the lower and upper bounds of the collapse loads of engineering structures involving mixture of random and interval uncertain system parameters. Consequently, the bounds of structural reliability against collapse failure can be efficiently estimated. The applicability and accuracy of the proposed hybrid uncertain limit analysis are critically justified through the investigations on both academic and practically motivated engineering structures.