Post Buckling Analysis of Silos and Optimization of Additional Stiffeners

Silos are probably the common form of large engineering shell structure in service. The high rate of structural failure in these structures must be considered by the designer and the complexity of their behavior. The paper presents buckling and post-buckling of silos under axial compression using a time-integrated finite element model as well as the analysis and Experimental results. Since stiffeners have the vital role to support the pressure vessel and to maintain its stability, they should be designed for load and internal pressure of the vessel. A model of vertical pressure vessel and stiffeners are created and stresses are evaluated using mathematical approach and ANSYS software. The analysis reveals the zone of high localized stress at the junction of the pressure vessel and stiffeners due to operating conditions. The results obtained by both the methods are compared. The analyses provide significant new insight into the mechanisms underpinning collapse behavior of the shells. The tests which are carried out on cylindrical silo models, the measurement of the initial imperfections and the numerical analysis of the shells are presented.