Virtual Test Approach of Titanium/Composite in Service Repair, Installed on Certified Composite Flap

Abstract

Virtual test methods can contribute to reducing the great effort for physical tests in the development of composite structure and in particular on the In-service Repair. The present work describes an approach for virtual testing of titanium/composite repair based on the Building Block Approach and the Finite Elements Method. Building on a multitude of physical tests on composite panels and joints, adequate sub-models are developed, validated and the results show that the method used for the substantiation of the generic repairs (GREOs) compared with test results is conservative. This thesis intends to provide a hierarchical virtual testing approach, which enables the prediction of the failure behavior and the strength of composite In-service repairs by means of validated FEM simulation. In particular the objective of this work will be to investigate the damage mechanisms in composite bonded skin/stringer constructions with metallic (titanium) bolted repair under uniaxial (in-plane/out-of-plane) loading conditions as typically experienced by aircraft flap skin panels.