Abstract:Composites C-shape ribs are made of carbon fiber fabric prepreg on the male moulds under certain curing
process. A coordinate measuring machine is used to measure the surface of the moulds, the inner surface of the ribs under
three conditions (three flanges closed, large end cut and three flanges trimmed after large end cut), and the outer surface of
the ribs when the large end is cut and the three flanges are trimmed. The springback of the ribs are measured and analyzed.
The results shows that the springback compensation of the two side flanges of the ribs is 1.35°, and the springback compensation
of the large end flange is 0.32° when the three flanges are closed. The springback results varied a lot before and after
the large end is cut, but varied little before and after the flanges are trimmed. The springback compensation is 1.69° for the
two side flanges, and 1.62° for the big end flange when the ribs are cut at the large end.