• In-situ stamp forming monitoring using fiber-optic-based shape sensors is proposed. • Real-time curvature and shape changes during stamp forming are measured. • Faster stamping speed improves molding accuracy of composites. • Slower speed induces fiber waviness due to viscoelastic effects. Stamp forming is a promising method for producing high-performance thermoplastic composites at high rates. However, the deformation mechanism of composites during forming is not well understood and optimizing the molding conditions is challenging. In this study, an in-situ deformation monitoring methodology for stamp forming using embedded fiber-optic-based shape sensors is proposed. First, real-time deformation measurement in stamp forming using the sensor is performed, confirming that this methodology is an effective means for deformation measurement. Then, using this method, stamp forming is performed at fast or slow stamping speeds to investigate how this parameter affects the deformation mechanism. The results reveal that a faster stamping speed (28 mm/s) improves molding accuracy, whereas a slower speed (5.6 mm/s) induces fiber waviness (amplitude of 0.14 mm, wavelength of 6.36 mm) due to viscoelastic effects. This technology is expected to play a significant role in elucidating the forming mechanisms of stamp forming, efficiently optimizing forming parameters, and verifying simulation models.
Chikamori et al. (Sun,) studied this question.