Post-buckling finite element analysis of composite cylindrical panels in axial compression

The post-buckling behaviour of composite cylindrical panels in axial compression is investigated using the nonlinear finite element theory. A branch switching algorithm with an ‘eigenmode injection’ is discussed. The effect of the reinforcement angle on the buckling load, as well as the post-buckling behaviour of the panels, are analysed. Examples are considered for separated and closely spaced bifurcation points.

By varying the reinforcement angle of the panels from 0 to 90°, two kinds of buckling modes are discovered for asymmetric and unstable symmetric lowest points of bifurcation. Local minima for the secondary branches of geometrically perfect panels are no less than 15% of their buckling loads, while values of the buckling loads alter more than twice in this region.

A 16-node degenerated shell element with full integration scheme is used.