Validation and modeling of aeronautical composite structures subjected to combined loadings: The VERTEX project. Part 2: Load envelopes for the assessment of panels with large notches

One of the important issues in the certification of composite aeronautical structures is large notches. In this paper, tests are carried out on technological specimens under tensile, shear and combined loadings using the VERTEX test rig presented in the first part of this publication. Strong interactions between postbuckling and propagation of cuts are observed. The specifically developed FE-SDIC methodology presented allows a first dialog between calculation and testing. The Discrete Ply Modeling method is able to compute the onset of failure in such complex tests. New test responses called “envelope curves” are proposed and are obtained by following a load path that allows the behavior of the notched structure to be validated for certification purposes. This methodology should eventually lead to a new vision of the test pyramid with the help of “Predictive Virtual Testing” procedures.