Sandwich pipes can be a potentially optimal system for use in deep-water
applications. In recent years, there has been considerable interest in understanding
the stability characteristics of these pipes under the governing loading conditions,
with the aim of generating optimal design. External hydrostatic pressure is a critical
loading condition that a submerged pipeline experiences during its installation and
operational period.
This article presents an analytical approach for estimating the bucking capacity of
sandwich pipes with various structural configurations and core materials,
subject to external hydrostatic pressure. The influence of adhesion between the
core layer and inner or outer pipes is also a focus of this study. Beside the
exact solution, two simplified equations are developed for estimating the
buckling capacity of two configurations commonly used in practice. Details of
both the exact and simplified analytical formulations are presented and the
required parameters are defined. The efficiency and integrity of the proposed
simplified solutions are compared with a solution developed by other researchers.
A comprehensive series of finite element eigenvalue buckling analyses was
also conducted to evaluate the accuracy and applicability of the proposed
solutions.