Abstract
Process-induced residual strain causes unexpected shape distortion, leading to premature failure and high manufacturing cost. Cure process simulation is an effective way to optimize the cure process in a reasonable manner. Accurate material properties (i.e., shrinkage strain and elastic modulus change during curing) are vital for high-fidelity simulations. This study first evaluated chemical cure shrinkage of carbon fiber reinforced plastic (CFRP) laminates with interlaminar-resin layers. Transverse and through-thickness strain of a typical UD laminate and a unique UD laminate, whose interlaminar-resin layers were aligned in the through-thickness direction, were measured by fiber Bragg grating (FBG) sensors to clarify the effect of the interlaminar-resin layers on the cure shrinkage. Next, the cure process was simulated by fully integrating the in-situ strain measurement. We embedded two FBG sensors (i.e., short tail FBG and long tail FBG) into a UD laminate. The material properties were then determined based on the different responses of the two FBG sensors due to the shear-lag effect at the edge of the sensors. Finally, cure process simulation was carried out and compared with the experiment. The simulated strain agreed well with the measured value, confirming the validity of the proposed approach.
