Sandwich pipes that combine structural performance with thermal insulation in their design are viewed as a light-weight alternative to pipe-in-pipe systems, in which the core material is used only for thermal insulation purposes. Incorporating functionally graded interlayers into the sandwich pipe design may help improve adhesion at the interfaces between the core layer and inner and outer pipes which has been identified as one of the major factors affecting sandwich pipe performance. In this paper, sandwich pipes with two thin functionally graded interlayers between the core layer and inner/outer pipes are investigated in the context of elasticity theory. Closed form analytical solutions are derived for stresses and displacements in the pipes subjected to internal and/or external pressure. Comparative analysis of sandwich pipes with and without functionally graded interlayers is performed and beneficial effect of graded interlayers on stresses and displacements in the pipe is established. (C) 2016 Elsevier Masson SAS. All rights reserved.
Financial support of this research by the Royal Society of Edinburgh and the Italian Academy of Sciences under International Exchanges Bilateral Programme grant is gratefully acknowledged.
- functionally graded material
- elasticity theory
- sandwich pipe