As part of the InSiTe project funded by the German Research Foundation (DFG), the Institute for Production Engineering and Machine Tools (IFW) has developed and researched an innovative strain-sensitive consolidation roller for laser-based automated fiber placement (LAFP).

The roller s sensitivity comes from glass fiber sensors embedded in the roller s elastic surface, which detect Rayleigh backscattering of laser light to measure strain with high spatial resolution, down to 0.65 mm between data points. This enables precise monitoring of thermal and mechanical loads critical to producing high-quality, recyclable thermoplastic composites.

To maximize accuracy, IFW developed methods to compensate for disturbance variables inherent to the LAFP process, such as laminate thickness and changing boundary conditions. The integration approach, embedding glass fibers in grooves using elastic silicone adhesives, demonstrated the highest strain sensitivity in experimental trials.

A thermodynamic model of the LAFP process was also created to calibrate the sensor and correlate measured strain with temperature data. The final validation of the sensory consolidation roller is planned over the coming weeks in real production of a flat laminate, marking a milestone in process control and quality assurance for thermoplastic composite manufacturing.

Source: www.ifw.uni-hannover.de