Abstract:
The curing process is one of the key factors for the performance of resin matrix composites, it is necessary to carry out the effective online monitoring for the curing process. In this paper, a method for monitoring the curing process of resin matrix composites was proposed after integrating the two technologies based piezoelectric transducers: The electromechanical impedance technique and the guided wave technique. The interrelation between the curing time and energy of guided wave was analyzed. The variation of signal resonance peaks of electromechanical impedance with the curing time was also discussed. The results show that in resin matrix composites curing, the amplitude of the guided wave signal and the formant frequency of the electromechanical impedance signal both decrease first, then increase and gradually stabilize, which indicates a series of changes in the curing process of resin matrix composites. Taking the case of the curing monitoring of the unidirectional carbon fiber (T300)/thermosetting epoxy prepreg, this monitoring method based on piezoelectric transducers for curing of T300/thermosetting epoxy composite is verified. Under the condition of vacuum bag pressure and curing temperature of 120℃, 20 min is the gel time point and 65 min is the completion time point for T300/thermosetting epoxy composite. The proposed curing monitoring method provides the basic data and technology basis for the design and optimization of the molding process of resin matrix composites.