The lateral surface of a cylindrical structure, which is composed of a thin
tube embedded in a large outer medium, is submitted to a uniform external
pressure. The buckling pressure of such a structure, corresponding to a low
flexural state of the inner tube wall, is theoretically analyzed on the ba
sis of the asymptotic method. The theoretical results are compared with exp
erimental ones obtained from a compression test realized on an elastic tube
inserted in a foam. It is found that the Euler pressure and the associated
buckling mode index strongly depend upon the rheological and geometrical p
arameters of both the tube and the surrounding medium. [S0021-8936(00)00201
-4].