Preliminary Study of a New Design Criterion for Shells under Axial Compression

摘要

An attempt is made to find design criterion for axially compressed shells. The211u001ecurrent design criterion NASA-SP-8007 (27) uses an empirical knockdown factor. 211u001eThe knockdown factor is a lower bound to all known experimentally determined 211u001ebuckling loads. Because many shells have a higher buckling load than the lower 211u001ebound a new design criterion is desirable. It is felt that the new design 211u001ecriteron should incorporate measured initial imperfection data. To provide 211u001einsight in the buckling problem of thin walled shells several theoretical 211u001eimperfection models for determining the buckling load of isotropic circular 211u001ecylindrical shells are discussed. The results of the models are compared with 211u001eexperimental data and with the lower bound design method of NASA-SP-8007 (27). 211u001eThe models vary from a simple cosine axisymmetric imperfection model to multi-211u001emode imperfection model. The experimental imperfection data used in the models 211u001eare from the International Imperfection Databank (6).