Basic modes of crack propagation through the interface in a polymer layered structure

摘要

The multi-layered structure components of dissimilar materials are used in many engineering applications to protect the base structure from outer damage. Typical examples of coated structures are pipes with the dimensional addition of protective layers (multi-layer pipes). The purpose of this development is to protect the main (functional) part of the pipes from damages (e.g. surface scratches, internal crack propagation). In the contribution the attention is paid to cracks existing and propagating in inner protective layer. In many cases the cracks are stopped at the interface between protective and functional layers. The important task is to decide if they penetrate further through the interface in the bulk material and thus cause the failure of the system. The critical stress for the crack propagation through the interface depends on the relation between bulk and coating materials as well as on the crack geometry. All these important topics are taken into account and their effect on crack propagation is broadly discussed.