Guidelines for the determination of the parameters in Puck’s action plane strength criterion

Inter-fibre fracture (IFF) of a UD laminate with a polymer matrix is governed by the stresses σn, τnt, τn1 on a fracture plane parallel with the fibres. This plane can be found as the stress action plane with the highest stress exposure factor calculated from a (σn, τnt, τn1)-strength criterion by Puck. The new criterion can be adapted to test results by up to seven independent parameters. This paper emphasises the procedure to provide the three strength parameters and gives recommendations for the choice of the four inclination parameters. In particular it is the objective of the paper to point out the limits of validity of those inclination parameters which cannot be determined by simple experiments. The relevance of each parameter is elucidated with particular respect to reaching a consistency of the 3D formulation of the Puck-criterion and its simplified 2D formulation.