BUCKLING OF STIFFENED 2-LAYERED SHELLS OF REVOLUTION WITH A CIRCUMFERENTIALLY CRACKED UNBONDED LAYER

Orthotropic stiffness layer models are derived for buckling of eccentrically stiffened shells of revolution with two unbonded orthotropic layers: 1) both of which are uncracked, and 2) one of which is circumferentially cracked. The two models are used in conjunction with a theory for buckling of eccentrically stiffened, circular cylindrical shells with multiple orthotropic layers to assess the importance of including the ablative layer in design calculations for two-layered (metallic plus ablative) re-entry vehicle shells. It is demonstrated in the present analysis that the ablative layer, even when circumferentially cracked and not bonded to the metallic layer, actually dominates the buckling stiffness of a re-entry vehicle shell and, hence, provides an already available source of stiffness for design calculations. However, the current treatment of the ablative layer is to either ignore it completely (an unduly conservative approach) or to regard it as uncracked and perfectly bonded to the metallic layer (an unconservative approach). © 1969 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.