Fibre-orientation measurements in short-glass-fibre composites. Part I: automated, high-angular-resolution measurement by confocal microscopy

In this first paper, the confocal technique for fibre-orientation distribution measurement is described and the associated errors discussed in detail. With this technique, fibres are followed for short distances into the bulk of the sample enabling a complete description of the fibre-orientation distribution tensor. Novel image processing and management routines have been implemented in order fully to automate the data acquisition, and consequently significant sample areas (several square mm) can be analysed within hours. In a follow-up paper the fibre-orientation measurements from the confocal technique will be used to evaluate independently the errors in the standard 2D image analysis technique of fibre-orientation measurement.