Buckling assessment of cylindrical steel silos under wind loading

Document Type : Original Research

Authors
A. Moazezi Mehretehran
S. Maleki
Department of Civil Engineering, Sharif University of Technology
Abstract
Thin-walled cylindrical steel silos are susceptible to instability under wind pressure when they are empty or only partially filled. This paper investigates numerically the wind buckling behavior of three steel silos. They are composed of flat sheets with stepped walls with multiple discrete steps in thickness.

The vertical and circumferential distributions of wind loading were adopted from Eurocode. Two proposed circumferential pressure distributions for an isolated silo and a silo in a group were taken into consideration. Where the silo does not have a closed roof, an additional uniform value of internal underpressure coefficient should be considered, thus increasing the net stagnation inward pressure on the silo walls. The effects of additional inward pressure on a vented silo with a small opening were specially explored through the paper. Therefore, a total of four different load cases were examined in this paper: isolated load case and grouped load case, each of them for silos with closed roof and for vented silos.

Two types of analyses were undertaken for the wind buckling assessment of the silos: the linear elastic bifurcation analysis and the geometrically and materially non-linear analysis. According to non-linear load-deflection curves, the buckling in all load cases was of snap-through type. The curves showed more non-linear charecteristics in group load case. Moreover, in general, the wind buckling resistance of silos under grouped load case was less than isolated load case. Finally, silos with closed roof compared with vented silos with a small opening, exhibited about 40% more wind buckling resistance.

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Subjects

[1] EN 1991-4. Eurocode 1: Actions on structures - Part 4: Silos and tanks. Brussels: CEN; 2006.
[2] Rotter JM. Pressures, stresses and buckling in metal silos containing eccentrically discharging solids. Festschrift Richard Greiner, Celebr Vol 60th Birthd Prof Richard Greiner, TU Graz, Austria 2001:85–104.
[3] Sadowski AJ, Rotter JM. Study of buckling in steel silos under eccentric discharge flows of stored solids. J Eng Mech 2009;136:769–76.
[4] Sadowski AJ, Rotter JM. Buckling of very slender metal silos under eccentric discharge. Eng Struct 2011;33:1187–94.
[5] Cao Q, Zhao Y. Buckling design of large eccentrically filled steel silos. Powder Technol 2018;327:476–88. doi:https://doi.org/10.1016/j.powtec.2018.01.001.
[6] Sadowski AJ, Rotter JM. Slender thin cylindrical shells under unsymmetrical strip loads. Thin-Walled Struct 2012;61:169–79.
[7] Wang P, Zhu X, Liu M, Li Y. Buckling behaviors and simplified design method for steel silos under locally distributed axial load. J Constr Steel Res 2017;134:114–34.
[8] Greiner R, Guggenberger W. Tall cylindrical shells under wind pressure. In: Rotter JM, Teng JG, editors. Buckling Thin Met. Shells, London: 2004, p. 198–206.
[9] Greiner R. Cylindrical shells: wind loading. silos Fundam. theory, Behav. Des., vol. 17, London: E & FN Spon; 1998, p. 378–99.
[10] Sadowski AJ, Fajuyitan OK, Wang J. A computational strategy to establish algebraic parameters for the Reference Resistance Design of metal shell structures. Adv Eng Softw 2017;109:15–30.
[11] Rotter JM. Shell buckling design and assessment and the LBA‐MNA methodology. Stahlbau 2011;80:791–803.
[12] EN 1993-1-6. Eurocode 3: Design of steel structures - Part 1-6: Strength and stability of shell structures. Brussels: CEN; 2007.
[13] Kebeli H V, Bucklin RA, Gurley K, Reinhold T. Wind pressure coefficients of conical roofs on grain bins. Americas (Engl Ed) 2001:1.
[14] Macdonald PA, Kwok KCS, Holmes JD. Wind loads on circular storage bins, silos and tanks: I. Point pressure measurements on isolated structures. J Wind Eng Ind Aerodyn 1988;31:165–87.
[15] Macdonald PA, Holmes JD, Kwok KCS. Wind loads on circular storage bins, silos and tanks. II. Effect of grouping. J Wind Eng Ind Aerodyn 1990;34:77–95.
[16] Macdonald PA, Holmes JD, Kwok KCS. Wind loads on circular storage bins, silos and tanks III. Fluctuating and peak pressure distributions. J Wind Eng Ind Aerodyn 1990;34:319–37.
[17] Sabransky IJ, Melbourne WH. Design pressure distribution on circular silos with conical roofs. J Wind Eng Ind Aerodyn 1987;26:65–84.
[18] EN 1993-4-1. Eurocode 3: Design of steel structures - Part 4-1: Silos. Brussels: CEN; 2007.
[19] Nielsen J, Rotter JM. On the definition of design values for loads on silos and tanks. Adv Struct Eng 2017:1369433217746348.
[20] Ansourian P. On the buckling analysis and design of silos and tanks. J Constr Steel Res 1992;23:273–94.
[21] Greiner R, Derler P. Effect of imperfections on wind-loaded cylindrical shells. Thin-Walled Struct 1995;23:271–81.
[22] Chen L, Rotter JM. Buckling of anchored cylindrical shells of uniform thickness under wind load. Eng Struct 2012;41:199–208.
[23] Zhao Y, Cao Q, Su L. Buckling design of large circular steel silos subject to wind pressure. Thin-Walled Struct 2013;73:337–49.
[24] EN 1991-1-4. Eurocode 1: Actions on structures - Part 1-4: General actions - Wind actions. Brussels: CEN; 2005.
[25] Sadowski AJ, Rotter JM. Steel silos with different aspect ratios: I—Behaviour under concentric discharge. J Constr Steel Res 2011;67:1537–44.
[26] Dassault Systèmes Simulia. Abaqus CAE User’s Manual. 2012.
[27] Sadowski AJ, Rotter JM. Solid or shell finite elements to model thick cylindrical tubes and shells under global bending. Int J Mech Sci 2013;74:143–53.
[28] Kuczyńska N, Wójcik M, Tejchman J. Effect of bulk solid on strength of cylindrical corrugated silos during filling. J Constr Steel Res 2015;115:1–17.
[29] Song CY. Effects of patch loads on structural behavior of circular flat-bottomed steel silos. Thin-Walled Struct 2004;42:1519–42.
[30] Maleki S, Mehretehran AM. 3D wind buckling analysis of long steel corrugated silos with vertical stiffeners. Eng Fail Anal 2018.
[31] Raeesi A, Ghaednia H, Zohrehheydariha J, Das S. Failure analysis of steel silos subject to wind load. Eng Fail Anal 2017;79:749–61.
Modares Civil Engineering journal
Volume 19, Issue 3
September and October 2019
Pages 227-239