Reducing performance variations of compression moulded long glass fibre reinforced thermoplastics by targeted reinforcement

Abstract

Long glass fibre compression mouldings are prone to significant variations in mechanical properties. Stiffness and strength tend to vary across an individual moulding and in addition there are also variations when different mouldings are compared. Compression mouldings in the form of a top hat section were produced. This component was first modified to have ribs, then samples of both batches were reinforced with a thin thermoplastic composite plate with continuous fibres. In this way, four different batches were produced, which were tested under 3-point-bending. Further, this work investigated the changes in mechanical properties across the manufactured top hat section mouldings. Tensile test results strongly indicate that the scatter of mechanical properties increases towards the edges of the compression moulding. When the mouldings were tested under 3-point-bending, the experimental results were prone to a large scatter and it was not possible to predict the position of failure or the failure mode. However, this work successfully demonstrated that a targeted reinforcement of the moulding with continuous fibres can significantly reduce the performance variations, particular under loading with large strain. The findings of this work could lead to the development of new lightweight structural components, where there is a need for integrating functions into the moulding in order to reduce weight and costs for mass production.