S. Bahadir Yuksel

Finite element analysis and practical modeling of reinforced concrete multi-bin circular silos

Stress resultants in overlapping wall regions (intersection walls) of multi-bin circular silos require a significant computational effort to determine forces due to structural continuity. This paper presents a practical equivalent beam model for computing design forces along the silo walls when subjected to various internal and interstice loadings. The equivalent beam model of intersection wall was developed based on the effective length concept, and verified in a comprehensive series of finite element (FE) analyses of a cluster of four silos for various silo-wall thicknesses. The influence of wall thickness on hoop forces and bending moments acting on interstice and external walls were also examined, and simple empirical expressions were presented for design applications. The proposed beam model yields an accurate estimation of bending moments and hoop forces with a maximum 7% deviation compared with those obtained from detailed FE models.

Design Formulas for the Groups of Six Cylindrical Silos Due to Interstice Loadings

Different and huge amounts of granular materials can be stored in and between the cells of the grouped reinforced concrete cylindrical silos. The determination of design forces acting on these grouped silos requires significant computational effort due to structural continuity and the force transfer between the adjacent silos. In this conjunction, the present study carried out a series of two-dimensional linear elastic analyses for various groups of six cylindrical silos to examine their behaviors against interstice loadings. A detailed parametric study was performed by varying the silo-wall thickness, intersection wall thickness and the intersection wall lengths of the groups of six cylindrical silos in order to confirm their effectiveness on the resultant design forces. Bending moments, hoop forces and shear forces occurring at the interstice walls due to interstice loadings were computed with finite element analyses. Based on the results of the present numerical analyses, the design formulas were introduced and the design coefficients were proposed to compute the design forces without necessitating any finite element analyses.

Design Force Estimation Using Artificial Neural Network for Groups of Four Cylindrical Silos

The computation of design forces for the reinforced concrete groups of four cylindrical silos (GFCS) is fairly difficult because of the continuity of the walls between the adjacent silos. In this study, the efficiency of the artificial neural network (ANN) in predicting the design forces and the design moments of the GFCS due to interstice and internal loadings was investigated. Previously obtained finite element (FE) analyses results in the literature were used to train and test the ANN models. Each parameter (silo wall thickness, intersection wall thickness and the central angle spanning the intersection walls of the GFCS) affecting design forces and moments was set to be an input vector. The outputs of the ANN models would be the bending moments, hoop forces and shear forces at the supports and crowns of the interstice walls due to interstice loadings; the maximum axial forces and maximum bending moments at the external walls due to internal loadings. All the outputs of the ANN models were trained and tested by three-layered 11 back-propagation methods widely used in the literature. The obtained results presented that these 11 different methods were capable of predicting the design forces and the design moments at the interstice and external walls of the GFCS used in the training and testing phases of the study.