Snap Through And Post Buckling Behavior Of Cylindrical Shells Under The Action Of External Pressure

This Note contains curves of buckling coefficients and formulas for the calculation of the critical external pressure of finite length, circular cylindrical shells with sandwich walls. The facings of the sandwich are isotropic, of equal or unequal thickness, of the same or different material, and their individual stiffness. is not taken into account. The sandwich core is isotropic or orthotropic having natural axes in the axial, tangential, and radial directions of the cylinder. If the cores are very rigid, the method yields results that are substantially those of von Mises.

Methods and equipment haven been developed to determine the dynamic tensile characteristics of paperboard and corrugated fiberboard. A flywheel-type test machine has been constructed and suitable instrumentation has been developed. Preliminary investigations of paperboard indicate that tensile strength increases approximately as a logarithmic function of the loading rate.