Design and Fabrication of Protective Corrugated Tunnels for Using in Aerospace Structures

Corrugated tunnel is a pipe, which its outer surface is corrugated and is generally used for fluid transfer in different industries. Owing to complicated geometrical structure of corrugated tunnels, very limited numbers of closed-form equations have been presented for analysis of their mechanical behavior. In the present study, a mathematical model is proposed for strength and buckling analysis of corrugated pipes. In addition, an algorithm is presented for designing of corrugated tunnels. In order to verify the presented model, its results were compared with those obtained by finite element method (the ABAQUS software was used) and a good agreement was observed. Finally, some corrugated tunnels were designed, fabricated and tested for a special industrial application. Critical pressure values obtained from the tests were less than those calculated from the theoretical method, which could be due to fabricated flaws.