An experimental investigation into the buckling and post-buckling of CFRP shells under combined axial and torsion loading

摘要

The results of an experimental study of the buckling and post-buckling behaviour of four unstiffened thin-walled CFRP cylindrical shells are presented. The test equipment allows axial and torsion loading, applied separately and in combination, using a position control mode, and includes a laser scanning system for the measurement in situ of the geometric imperfection as well as of the progressive change in deformations. The results identify the effect of laminate orientation, show that the buckling loads are essentially independent of load sequence and demonstrate that the shells are able to sustain load in the post-buckling field without any damage. The measured data are fundamental for the development and validation of analytical and numerical models and contribute to the definition of applicable strength design criteria of composite cylindrical shells in the post-buckling field, with the final aim of a larger structure weight saving.