Abstract
The problem of debonding of a laminated cylindrical shell is considered for the case where a pair of self-equilibrating line loads act through the center of a pre-existing delamination. The problem is approached as a moving boundary problem in the calculus of variations, yielding a set of self-consistent equations governing the intact laminate and governing the debonded segments of the structure, viewed both as a composite structure and individually, for this class of problems. In addition to the corresponding boundary and matching conditions, the transversality conditions which define the location of the variable boundary of a contact zone and of the delamination itself are similarly obtained. The latter results in the energy release rates which are seen to be a function of mode II or a combination of mode I and mode II fracture depending upon the presence or absence of the contact zone. A closed form analytical solution is determined and numerical results demonstrating characteristic behavior are presented. The system is seen to exhibit relatively complex behavior for the simple loading considered. General trends of the behavior of the system as a function of its material parameters, of the bond strength and of delamination size are observed.