Linear elastic mode-based reliability approach for single-bay portal frames

Journal article

Nowadays, the semi-probabilistic design approach using partial safety factors is by far the most widely used technique for the design of new industrial buildings. It is believed that the method delivers a safe design with respect to a minimum degree of reliability as prescribed by EN1990. This paper aims at describing the behaviour of single-bay portal frames at a system level based on analytical reliability approach with dominant failure modes. In the case of extreme loading where cross-sections attain their ultimate resistances, the failure modes of single-bay portal frames can be described using a limited number of critical sections. The limit state or performance function is hence reduced to the assessment of those critical sections. Through the use of the well-known force-based method, an analytical matrix formulation of the problem can be proposed and can be easily implemented. For each variable included in the performance resistance of the system, probability density functions can be calculated (Monte Carlo method) and their influence on the system's reliability level investigated. Comparison can then be made with the results obtained with the partial safety factor method. As a case-study, the influence of the building shape (height-to-span) and load ratio on the reliability of single-bay portal frames is investigated.

Authors: Molkens, T; Rossi, B

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Structures
• Volume: 34
• Pages: 2205-2217
• Publication date: 2021-09-13
• Acceptance date: 2021-08-27
• DOI: 10.1016/j.istruc.2021.08.113
• EISSN: 2352-0124
• ISSN: 2352-0124
• Language: English
• Keywords: partial safety factor; Monte Carlo; probabilistic analysis; steel portal frame; reliability assessment; mode-based analysis; FFR