Micromechanical modelling of shear deformation of a 90°-ply in Glare® at elevated temperatures

This work focuses on modelling the interlaminar shear deformation of a 90°-composite glass fibre epoxy ply, using finite-element analysis (FEA). The investigated transverse layer is part of a typical Glare® lay-up. This approach uses a unit cell of a single, resin embedded fibre, assuming hexagonal fibre alignment. This representative volume element (RVE) is provided with periodic boundary conditions (PBCs). Matrix yielding and micro mechanical damage due to debonding at the fibre-matrix interface are the main consequences after interlaminar shear load is applied on the RVE. Temperature dependent material properties, thermal residual stresses of the 90°-layer and the Glare® composite, as well as the adhesive strength at the fibre-matrix interface are taken into account. Comparing the computational and experimental results shows that plastic matrix deformation and further occurring damage can be assigned to defined global shear loads at given temperatures. It is shown that the parameters concerning the interfacial strength have a large influence on the global shear behaviour of the RVE. Thus, the basis for further investigations is explored to give design criteria for given thermal and mechanical loads in structural applications.