Question

You are designing a vascular prosthesis made of woven Dacron and you would like to reinforce it with thin metal wires. The prosthesis has a cylindrical shape. The principal directions of stress are the axial and circumferential. What orientation would you choose for the metal wires to avoid rupture/delamination? Why? Explain in words and/or drawings.

Answer 1

As shown in figure this kind of configuration of the metal wire will provide more strength to the vascular prosthesis. In place of spiral configuration, we can also use metal wire rings which will provide better strength against circumferential stress. But this spiral configuration will provide strength against circumferential along with axial stress also. If the vascular prosthesis gets elongated along axial direction the corresponding radius of the rings will become short and it will prohibit the expansion of the vascular prosthesis along the circumferential direction.