Study on the Strength Reduction in Composite Structures due to Process-Induced Deformation
Takayuki SHIMIZU, Hiroki KOINUMA and Kanehiro NAGAI
Abstract:Process-induced deformation in composite parts affects their qualities and demands a lot of efforts for the compensation. In this work, the strength reduction after structural assembly due to process-induced deformation was investigated with L-shaped bending tests. The strengths of cured specimens after enforced shape compensations depended on the number of ply and the spring-in angle. Failure criteria of the L-shaped specimen were evaluated and the interlaminar tensile stress at the curved location was dominant for the thick specimens. However, an effect of the in-plane compression stress was found for the thin specimens. Pull-off tests of skin-stringer structures cured by normal tools and shape compensated tools were also conducted to valid the effects of the tool shape compensation. Key Words:CFRP, Structural assembly, Process-induced deformation, Residual stress, Delamination