Effect of interlaminar toughening layers on the diaphragm forming quality of carbon/epoxy prepreg

Diaphragm forming is a composite forming technique which is suitable for manufacturing composite components with relatively simple geometry such as wing spars and stringers of aircraft and composite structural beams for various applications. Unlike the conventional ply-by-ply lay-up onto a tool surface, this method creates a flat laminate preform first and then deforms it into a desired shape, which significantly reduces the processing time. Due to this advantage, diaphragm forming (also called hot drape forming particularly when the forming is carried out at an elevated temperature) is used in conjunction with automated tape laying (ATL) process to improve production rate.