Numerical Analysis of Cylindrical Steel Silos for Internal Pressure Assessment

Resumo

Silos are essential structures for the storage of granular materials, particularly within the Brazilian agro-industrial context. Proper structural design is crucial to ensure safety, durability, and performance throughout their service life. One of the main challenges in silo design lies in the accurate estimation of internal pressures exerted by stored materials, whose magnitudes and distributions vary according to the type of product, structural geometry, and operational conditions, such as loading and unloading. This study presents a three-dimensional numerical analysis based on the finite element method, aiming to investigate the structural behavior of a cylindrical steel silo, with a focus on the assessment of internal pressures. A numerical model was developed using the software Abaqus, employing an elastoplastic constitutive model based on the Drucker–Prager criterion to represent the behavior of granular materials. The silo walls, base, and stored material were discretized using C3D8R elements. The interaction between the grains and the silo structure was modeled through a surface-to-surface contact formulation. The applied loading considered only the self-weight of the stored material. Boundary conditions included full restraint of all degrees of freedom at the base of the silo and a vertical displacement restriction at the bottom of the bulk granular material. Model validation was conducted using experimental results from Cheung (2007), showing good agreement between numerical predictions and experimental data. Additionally, the numerical results were compared with classical theoretical approaches, such as the Janssen and Reimbert formulations. The findings demonstrate that the proposed numerical model is effective in predicting internal pressures and structural deformations, offering a reliable and practical alternative to the limitations of full-scale experimental testing and contributing significantly to the improvement of silo design methodologies.