Investigation of thermal effects on silos caused by thermal differentials between stored solid and the silo structure

摘要

Thermally caused stress in silos have the potential to become critical in some cases. Therefore, most codes and standards require that silos are designed to resist thermal stress due to thermal differentials between stored material and the silo structure. However, very few of them include explicit requirements concerning the design of the silos in effectively combatting thermal effects. The research presented here disseminates thermal effects on reinforced concrete ground-supported cylindrical silos, which has received little attention to date. A three-dimensional numerical model, taking into account bulk material-silo wall interaction, was performed with the ANSYS commercial program, which is based on the finite element method, to evaluate the distribution and the magnitudes of bulk material pressure in the silos under thermal effects. The results of a parametric study, which examines the effects of varying aspect ratios, wall thicknesses and wall friction angles on the thermal response of reinforced-concrete cylindrical silos, is presented and the results from the numerical method are compared with the findings obtained via EN 1991-4. The finite element analysis revealed that the computed thermal material pressure is smaller than the design pressure obtained via EN1991-4 over a wide range of aspect ratios, suggesting that the design process is particularly conservative. Additionally, results reveal that in contrast to both wall thickness and wall friction angle, the aspect ratio may significantly affect the magnitudes of the responses of the reinforced concrete cylindrical silos under thermal effects.