نوع مقاله : مقاله پژوهشی
عنوان مقاله English
نویسندگان English
Steel hemispherical shells are highly sensitive to initial geometric imperfections, resulting in a considerable gap between theoretical buckling capacity and actual performance. This study presents a probabilistic assessment of the buckling capacity of steel hemispherical shells with random geometric imperfections, modeled as a continuous random field using the Karhunen-Loève expansion. The effects of imperfection amplitude and correlation length on critical buckling load are investigated. Nonlinear behavior is simulated via the arc-length method and finite element analysis, with statistical evaluation through Monte Carlo simulation. Results show that a fivefold increase in imperfection amplitude causes approximately a 48.5% drop in critical load, while correlation length exhibits a dual effect, with maximum capacity reduction at intermediate values. The buckling capacity distribution is fitted with the Weibull distribution, yielding a probabilistic load-carrying reduction factor of 0.28 at the fifth percentile. Compared with the ~0.50 factor commonly recommended in classical design guidelines, this indicates that the traditional deterministic factor may be non-conservative, highlighting the need to replace conventional factors with probabilistic criteria based on accepted risk levels for more optimal and economical design while maintaining structural safety.
کلیدواژهها English
