Mechanical modeling, seismic fragility, and correlation issues for groups of spherical pressure vessels

Abstract A roadmap is outlined for determining comprehensive seismic fragility curves (single or groups of) spherical pressure vessel structures commonly found in oil refineries. The developed modeling techniques aim to strike a balance between accuracy and computational efficiency, with focus on capturing the most pertinent failure modes relevant these structural types. First, set of “partial” fragilities determined based each vessel’s fill ratio, as response varies substantially depending amount liquid content. Considering that assessment process invariably involves simultaneous consideration such partial fragilities, Monte Carlo-based approach employed their combination. results naturally depend level correlation employed, but can be almost perfectly matched by simpler analytical methods edge cases full zero correlation.