Steering of carbon fiber/thermoplastic pre-preg tapes using laser-assisted tape placement

The weight saving benefits of fiber-reinforced composite materials in structural applications are well established. However, there is an increasing requirement to develop processing techniques that can produce highly repeatable and accurate components more efficiently than using autoclave processing; Laser-assisted Automated Tape Placement (LATP) in-situ consolidation of thermoplastic composites has significant potential to fulfil this requirement. In addition, LATP can process layers with Variable Angle Tow (VAT), an advanced tailoring option that allows modification of load paths within the laminate to result in more favorable stress distributions and improved laminate performance. Studies of VAT laminate manufacture using dry fiber placement and thermoset pre-preg tape placement have been previously reported. This work examines the ability to produce VAT laminates from carbon fiber/PEEK pre-preg tapes using LATP. A VAT laminate was successfully manufactured which had three steering radii of 800 mm, 600 mm and 400 mm with little defects. Characterization and mechanical testing were completed on steered samples to examine the effect of lay-down speed and radius on bond strength of steered tapes. Measurements showed that the width and thickness of the carbon fiber/PEEK tapes were changed during steering. Mechanical testing showed that bond strength was a function of lay-down speed, yet the effect of steering radius was inconclusive due to undesired failures.