Fabrication and Strength Assessment of Composite Corrugated Expansion Tube

A technique is proposed to develop a composite corrugated expansion tube which can achieve a prescribed axial extension when subjected to an internal pressure. The composite corrugated expansion tube was fabricated using annular carbon fabric/PU sheets via the vacuum-assisted resin transfer process. In forming the tube shape, the edges of each annular fabric/PU sheet are adhesively bound to the other two similar sheets at the outer and inner edges, respectively. A finite element model of the corrugated expansion tube is established using the shell elements of the finite element code ANSYS. To illustrate the applications of the proposed technique, the corrugated expansion tube that can sustain internal pressure of 82.73 MPa is developed and tested to verify the accuracy of the finite element model. It has been shown that compressive stresses are induced at the adhesive layers that are located at the outer edges of the corrugated expansion tube. The occurrence of such compressive stresses at the outer edge adhesive layers can increase the failure pressure of the corrugated expansion tube. The failure strength of the composite sheet dominates the incipient failure pressure of the tube. This type of failure mode makes the expansion tube design feasible for practical applications.