Cure monitoring and damage identification of CFRP using embedded piezoelectric sensors network

•A more effective and efficient method (SAFE) to calculate the propagation characteristics of Lamb-like waves in the vacuum bag molding process of prepregs.•The approaches for the in-suit monitoring and damage identification of the vacuum bag molding process of prepregs including the FBG sensors and PZT sensor network.•A new life-cycle monitoring method of CFRP during its manufacturing and service stages without degrading the structural integrity of the host composite structures. Because of the advantages of high specific strength and high specific stiffness, carbon fiber reinforced plastics (CFRP) have been the most ideal materials in the field of civil aviation. Cure monitoring in manufacturing process and damage identification in service stage of CFRP are always hot topics. The Semi-Analytical Finite Element (SAFE) method and micromechanical model are employed to analyse the propagation characteristics of the Lamb-like waves in a continuous flat aluminium plate attached to a viscoelastic unidirectional CFRP in semi-infinite half-space. Then the vacuum bag moulding process of prepregs is monitored using Fiber Bragg Grating (FBG) and piezoelectric sensors encapsulated in Stanford Multiactuator-Receiver Transduction (SMART) Layer. The calculated energy velocities and attenuations of guided waves show the same trends with the numerical results while curing. After the CFRP is demoulded, the damage identification experiments are carried out. By continuing to use the sensor network embedded in the manufacturing phase, the artificial damages can be precisely located. The results demonstrated that the life-cycle monitoring of CFRP can be achieved effectively by the piezoelectric sensors network.