The problem of propagation of interfacial failure in patched panels subjected to temperature change and transverse pressure is formulated from first principles as a propagating boundaries problem in the calculus of variations. This is done for both cylindrical and flat structures simultaneously. An appropriate geometrically nonlinear thin structure theory is incorporated for each of the primitive structures (base panel and patch) individually. The variational principle yields the constitutive equations of the composite structure within the patched region and an adjacent contact zone, the corresponding equations of motion within each region of the structure, and the associated matching and boundary conditions for the structure. In addition, the transversality conditions associated with the propagating boundaries of the contact zone and bond zone are obtained directly, the latter giving rise to the energy release rates in self-consistent functional form for configurations in which a contact zone is present as well as when it is absent. A structural scale decomposition of the energy release rates is established by advancing the decomposition introduced in W. J. Bottega, Int. J. Fract. 122 (2003), 89-100, to include the effects of temperature. The formulation is utilized to examine the behavior of several representative structures and loadings. These include debonding of unfettered patched structures subjected to temperature change, the effects of temperature on the detachment of beam-plates and arch-shells subjected to three-point loading, and the influence of temperature on damage propagation in patched beam-plates, with both hinged-free and clamped-free support conditions, subjected to transverse pressure. Numerical simulations based on closed form analytical solutions reveal critical phenomena and features of the evolving composite structure. It is shown that temperature change significantly influences critical behavior.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Applied Mathematics
- Growth path
- Interfacial failure