Seismic fragility analysis of pressurized piping systems considering ratcheting: A case study

• Published in: The International journal of pressure vessels and piping Vol. 169; pp. 26 - 36
• Main Authors: Ravi Kiran, A., Reddy, G.R., Agrawal, M.K.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2019
• Subjects: Fatigue-ratcheting; Floor response spectrum; Fragility; Incremental iterative response spectrum method; Response surface technique; Response surface technique; Incremental iterative response spectrum method; Fatigue-ratcheting; Floor response spectrum; Fragility
• ISSN: 0308-0161; 1879-3541
• DOI: 10.1016/j.ijpvp.2018.11.013

In the present paper, a methodology is presented for seismic fragility analysis of pressurized piping systems considering ratcheting. The methodology is applied for a typical piping system, which was considered for an international benchmark exercise on seismic margin assessment. A numerical tool, which was earlier validated with experimental results on ratcheting in pressurized piping components and systems, is used for evaluation of strains in piping system. Variations in damping and natural frequency of the piping system are considered for the fragility assessment in addition to ground motion variability. Twenty intra-plate earthquake records are considered for ground motion variability. Three performance levels are considered for the assessment: first one is the present design stress limit, remaining two are strain limits based on codal guidance and experiments. Response surface techniques in conjunction with Monte Carlo simulations are used for fragility evaluation. •Methodology for seismic fragility analysis of pressurized piping systems considering ratcheting is presented.•Performance of the piping system is characterized in terms of design stress limit and two strain limits.•The framework considers variation in damping, frequency in addition to the ground motion variability.•A case study on seismic fragility analysis for a typical piping system is presented.