The complexity and dispersivity of composite manufacturing can easily make composite produce voids

porosity

dry spots

warping

delamination and other defects or damage during the cure process. These defects will seriously affect the quality of the composite material. On-line in-situ monitoring of cure process is an important means to control and improve the quality of composite. This paper focuses on the cure monitoring of liquid composite molding (LCM)

which is increasingly used for producing high quality and complex composite structural parts. Firstly

the cure process of LCM is briefly introduced

and several physical parameters needed to monitor are analyzed. Secondly

the progresses on several on-line monitoring techniques for cure process are reviewed

including optical fiber method

ultrasonic method

electrical method and thermal method. Finally

the development trends and challenges of the cure monitoring for LCM are discussed.