Analysis for plastic buckling of thin-walled cylinders via non-classical constitutive theory of plasticity

The longitudinal compressive buckling loads of thin-walled cylinders in the yield region were analyzed by using both the incremental and the finite forms of a non-classical constitutive relation of plasticity (NCP). The relations of the critical stress u, vs the ratio between R (the radius) and h (the thickness of the wall) were derived. The critical stresses of the thin-walled cylinders made of aluminum alloys AMT and IIlT were analyzed and compared with the experimental results. Comparison shows that for the cylinders made of IIlT both forms of NCP can provide reasonable prediction ; but for those made of AMT, the result given by the finite form of NCP is satisfactory, while the critical stress predicted by the incremental form of NCP is about 25% higher than the experimental data. The capability of the NCP in the description of the material instability, the response of material under an abrupt strain disturbance and its easy application indicate that it may be of potential in the analysis of structural buckling. Copyright 0 1996 Elsevier Science Ltd