Влияние осевой силы на устойчивость стесненной цилиндрической оболочки

Abstract

The article considers a constrained cylindrical shell structure. It is a two-ply cylinder in which the inner metal shell (liner) contacts on the outer front surface with a composite shell formed by wound carbon-fibre tape. The design model of this structure is used, among other things, for metal composite cylindrical high pressure vessels. When such vessels are in use, there is a danger of liner delamination from a rigid composite shell, which refers to prohibitive defects. The deformation of the liner in the central part of the vessel occurs under the influence of internal pressure applied to both the cylindrical part and to the bottoms from which axial forces appear. The present work is aimed at studying the effect of these axial forces on the local buckling of the liner in the cylindrical zone of the vessel. The model of the structure deformation includes technological deviations characteristic of real products and a 3D stress-strain state, changing in real time. The calculation was carried out in the LS-DYNA software package in a dynamic formulation using 3D solid elements. For the target level of pressure, the moments of delamination of the vessel and the buckling of the liner are determined. A comparison of two design schemes (i) with and (ii) without axial force taken into consideration is carried out. The necessity of taking into account axial forces when designing metal composite high pressure vessels is shown.