The Internal Pressure Required in a Thin Cylindrical Shell under Bending and Compression, to Attain a Controlled and Stable Region of Crippling

摘要

A thin-walled cylindrical shell is subjected to bending, compression and enough internal pressure to limit crippling to a specified region of the shell. The assumption is made that the bending stress is uniform in the crippled region, varies linearly in the uncrippled region, and its intensity in tension and compression is such that the internal resisting load equals the externally applied load. The geometry of the shell is assumed such that the crippling loads are well within the elastic range. As a result of the above assumptions, bending stress coefficients are evolved which permit the computation of the required pressure to limit crippling to a specified region. With the applied loadings fixed, the shell thickness must be such that the tensile yield allowable stress is not exceeded in either the longitudinal or the circumferential direction. Formulas are given to enable a check that the latter condition is maintained. As the crippled region is allowed to extend, the required internal pressure may be decreased until one third of the skin is crippled. A further increase of the crippled region requires an increased internal pressure, however. (Author)