FEA of crack–particle interactions during delamination in interlayer toughened polymer composites

A numerical analysis was conducted, using previously obtained experimental results, to establish basic toughening mechanisms and fracture behaviour of an interlayer-toughened composite material, containing particulate modified interlayers. Aims of the analysis were to examine the influence of the particles on the plastic zone size that develops in front of the crack tip and to investigate interactions between the particles and the crack tip during elastic–plastic crack propagation. Under both loading modes particles did not promote yielding but induced micro-cracking. This was concluded to be the most dominant toughening mechanism within high particle content interlayers.