Compliance and ultimate strength of composite arterial prostheses

A further stage is reported in a comprehensive project aimed at developing new composites for soft tissue implants. The composite prostheses are made by a filament-winding technique comprising Lycra elastomeric fibres embedded in an elastomeric matrix of mostly Pellethane. New experimental results of compliance of filament-wound tubes and of the ultimate strength are presented and compared with theoretical predictions. It is shown that the functions of these properties in the winding angle are given by common composite material models. The compliance is predicted accurately by the expression based on a transformation of the principal elastic constants, whereby a maximum is expected at a winding angle of around 45 degrees. The ultimate strength is compared with two failure criteria, of which the maximum work criterion gives an excellent fit.