Plastic buckling of axially compressed cylindrical shells

The plastic buckling of cylindrical shells under axial compression is studied analytically and experimentally. Attention is given to both the nonlinear and nonconservative aspects of the stress-strain relation. The effect of unloading is investigated in an exact manner for a hinge model which is proposed and in both an exact and an approximate manner for a geometrically perfect shell. Thirty tests are reported on cylindrical shells of 2024-T4 aluminum with radius to thickness ratios of 120 through 10 and length to radius ratios of 0.20 to 7. Specimens were prepared with three different types of end conditions and were tested either through a ball and socket arrangement or flat ended between smooth bearing blocks. A simple (jy incremental theory gives results very close to J% deformation theory and does predict both buckling strength and the geometry of buckling for thick and moderately thick shells.