Finite Element Formulation for Farm Silo Analysis

A finite element formulation for the analysis of deformation and stress histories in circular farm silos, during sequential loading, has been established. The silage-silo global system is considered as an axisymmetric space structure with the silage assumed as an isotropic piecewise linear viscoelastic continuum contained in an elastic cylinder. The model permits simulation of filling sequence, friction along silo-material interface, and wall deformations. The analysis is formulated in the form of a boundary value problem and approximate solutions by finite element method is achieved through variational techniques. The devised formulation was applied to predict stress histories, deformations, and resulting capacities produced during sequential loading of a 24-ft x 70-ft (7.32-m x 21.35-m) top unloading drained silo, using material constitutive functions that have been previously established through triaxial creep tests on corn silage (mc=68%).