Generation and prediction methods for circumferential distribution changes in the braiding angle on a cylindrical braided fabric

Braided composites have an advantage in that their stiffness distribution can be changed by changing the orientation angle of the fibre bundle, called the ‘braiding angle’. To change the braiding angle on a cylindrical braided fabric, the longitudinal velocity of the mandrel and the angular rate of the spindle in a braider should be changed. However, these changes are only in the longitudinal direction and not in the circumferential direction.

A method for generating changes in the circumferential direction is proposed. The method sets an elliptical guide ring to provide fibres towards the longitudinal direction, called the ‘creating ellipse’, rather than a circular guide ring, called the ‘creating circle’ on a braider. Dynamic changes in the radius of the creating ellipse induce distribution changes in the circumferential direction. In validation studies comparing theoretical braiding angles with the experimental results, this method is proven effective for predicting circumferential distributions on a cylindrical braided fabric.