Enhancing the Robustness of Hybrid Metal-Composite Connections Through 3D Printed Micro Penetrative Anchors

Abstract

This work proposes a novel solution for manufacturing hybrid metal-composite joints, in which different pin shapes are evaluated for their capability to penetrate long carbon fiber epoxy composites successfully and for the mechanical behavior determined by each configuration. On the metal side, pins are manufactured by Laser Powder Bed Fusion (LPBF), downsizing the currently adopted solutions and, at the same time, developing new blocking features aimed at enhancing the mechanical properties of the joint. The different configurations were evaluated in two distinct experiments: the first to evaluate the induced defects in the composite substrate and the second to characterize the mechanical behavior of the joint. It emerges that smaller pins produce much less damage and misalignments in the composite structure with respect to the conventional pin solution, whereas the new “blocking features” configurations consistently increase maximum pullout load and energy with respect to the conventional pin solution, with the same level of fiber damage.