Using the classical laminated plate theory, a computer model has been developed to investigate stresses and strains of thick-walled sandwich pipes under internal pressure. The sandwich pipe is created using
non-reinforced material for the core layer and an alternate-ply material for the skin layers. Considering the complicated material properties of the skin layers reinforced by alternate-ply composites, the
analysis is based on treating typical sandwich pipes that are three-dimensional, cylindrical, and orthotropic. The computer model conducts stress and strain analysis of sandwich pipe with different winding
angles. The optimum winding angles have been found to be in the 60° range, and the strength of the sandwich pipe has been found to decrease rapidly when the core layer modulus is less than 20 GPa.