Anisotropy related "spring-in" of angled composite shells

Citation
Y. Ding et al., Anisotropy related "spring-in" of angled composite shells, POLYM POL C, 9(6), 2001, pp. 393-401
Citations number
16
Categorie Soggetti
Material Science & Engineering
Journal title
POLYMERS & POLYMER COMPOSITES
ISSN journal
09673911 → ACNP
Volume
9
Issue
6
Year of publication
2001
Pages
393 - 401
Database
ISI
SICI code
0967-3911(2001)9:6<393:AR"OAC>2.0.ZU;2-V
Abstract
During the manufacture of curved or angled shell composite structures, the enclosed angle of such structures tends to be reduced after cure. This phen omenon is referred to as "spring-in". It is believed that such distortion i s caused mainly by the significant difference between the in-plane coeffici ent of thermal expansion (CTE) and the through-thickness CTE. This might re sult in a larger out-of-plane contraction than the in-plane contraction dur ing the time that a composite structure is cooling down from the curing tem perature. In this paper, a 3-D Finite Element Analysis procedure was develo ped to predict "spring-in" resulting from anisotropy for both thin and thic k angled composite shell structures. The results of the FE analysis were ev aluated together with those from the analytical study and experimental inve stigation conducted by Jain at the Cooperative Research Centre for Advanced Composite Structures (CRC-ACS) in Australia. It was concluded, based on th ese results, that the FE model gives more accurate results than the analyti cal model, particularly for thicker composite shells. The corner radius eff ect, shell thickness effect, and lay-up effect on "spring-in", together wit h the effect of tool/part interaction on the total distortion were also dis cussed. Comparison was made with the experimental results reported by Radfo rd and Rennick.