The aim of this investigation is to study the effect of different imperfect
ion shapes on the inelastic stability of liquid-filled conical tanks and to
determine the critical imperfection shape that would lead to the minimum i
nelastic limit load. The study is carried out numerically using a self-deve
loped shell element used to simulate a number of conical tanks having an im
perfection shape in the form of Fourier series of equal coefficients. The F
ourier analysis of the buckling modes indicates that the existence of axisy
mmetric imperfection will lead to the critical inelastic limit load for con
ical tanks. (C) 1998 Elsevier Science Ltd. All rights reserved.