文档介绍：Journal of Sound and <ibration (1999) 224(3), 431}454
Article No. , available online at
FORCED VIBRATIONS OF SILOS LEADING TO BUCKLING
FERNANDO G. FLORES AND LUIS A. GODOY
Department of Structures, National ;niversity of CoH rdoba and CONICE¹, . Box 916,
5000 CoH rdoba, Argentina
(Received 25 August 1998, and in ,nal form 5 January 1999)
The large-amplitude force vibrations of steel thin-walled silos when empty are
investigated. The basic geometry con"guration modelled is a cylinder clamped at
the bottom with a top conical roof. Wind pressure distributions are assumed as
non-axisymmetric in the circumferential direction and with a rectangular impulse
or step distribution in time. Instability is identi"ed from "nite-element
computations of the time response of the shell using a criterion due to Budianski
and Roth. Results puted for silos made with plain as well as with
corrugated sheets, and the in#uences of geometric imperfections and the sti!ening
due to the roof are included in the analysis. The problems are also modelled with
static pressures using both continuation techniques and bifurcation analysis from
a linear fundamental path. Additional results have been obtained to estimate the
dynamic buckling load for step loading using energy procedures. All results are
computed using "nite-element codes developed by the authors.
( 1999 Academic Press.
1. INTRODUCTION
This paper reports on research carried out to elucidate the in#uence of dynamic
e!ects on the geometric instability of thin-walled metal silos. Wind-load buckling of
metal cylindrical silos causes considerable problems in many parts of the world.
Failure of such silos is illustrated in the photograph of Figure 1, for a group of
empty silos that collapsed in the province of Cordoba (Argentina) in 1993, under
wind gusts of 150 km/h. Instability occurs when the silos are empty, and may
induce transient de#ections in the cylindrical part, in the