Damage progression in composite cylindrical shells

A mechanical model is formulated to study delamination damage progression in laminated composite cylindrical shells subjected to dynamic loadings. The shell is modelled as an assembly of sub-shells joined by cohesive interfaces. The cohesive traction laws are defined as piecewise linear functions of the relative interfacial displacements and represent different physical mechanisms. By extending homogenization techniques formulated in the literature for intact shells and for shells with linearly elastic interfaces [1,2], the global displacement field is assumed to be piecewise linear in the thickness direction and incorporate jumps at the interfaces. The a priori imposition of interface continuity conditions then leads to a substantial reduction of the displacement unknown functions with respect to a classical discrete layer formulation, while its accuracy and efficacy in studying processes of dynamic delamination fracture are preserved