Postbuckling and failure of stiffened composite plates

摘要

Postbuckling and failure were studied analytically and experimentally for the stiffened composite plates. In the analysis, the stiffened composite plates were analyzed using the nonlinear finite element method. The progressive failure analysis was done by adopting the maximum stress criterion and complete unloading failure model. In the failure analysis, the considered failure modes are matrix failure, shear failure and fiber failure. In the experiment, the stiffeners were formed by the continuouslay-up of the skin. Therefore, the separation between the stiffener and the skin was not found even after final failure. A shadow moire technique was used to monitor the out-of-plane deformations of the plates. Piezoelectric film sensors were attached tothe plate and damages were detected by those. The analytical results on the buckling load, postbuckling behavior, and failure characteristics showed good agreement with the experimental results. The stiffened composite plate, which had been fabricated bysecondary bonding, was failed by debonding between the skin and the stiffener. The comparisons of the present occurring with the secondary bonding for the stiffened composite plate were conducted with respect to postbuckling behavior and failure mode inexperiments.