Influence of an optimized 3D-reinforcement layout on the structural mechanics of co-bonded CFRP joints

Primary aircraft structures benefit from the weight savings potential of carbon fiber reinforced plastics (CFRP) which is strongly determined by the applied structural joint design. Through-thickness reinforcements address the issue of an efficient load transfer between adherents and an improved joint damage tolerance. The innovative technology in the present work encompasses a cost and time efficient manufacturing along with a beneficial contribution to mechanical joint properties. The impact of an advanced reinforcement design on structural mechanics is investigated through quasi static single-lap shear (SLS) tests. A correlation between an extended set of design parameters and load bearing capability, strain to failure and joint stiffness is discussed. Recommendations are given for the significant improvement of each of these properties and for dealing with the arising trade-off.