Analysis of novel hybrid joints for composite struts

This paper considers a novel joining solution for a composite-metal hybrid strut component that predominately experiences axial loads (tension and compression). The hybrid interface proposed may achieve high structural integrity through a mechanical interaction between filament wound fibre-tows and surface features (pins) sculpted onto the metal in the joint region. A methodology to evaluate the proposed joining mechanism is presented through use of a two stage explicit Finite Element Analysis (FEA). Firstly, individual carbon fibre tows were modelled as a chain of one-dimensional beam elements with constant circular cross-section. This allowed for the prediction of the as-manufactured path of the tows on the structure. The fibre-tow beam elements were then converted to continuum elements for the tow cross section. A cylindrical casing of matrix material was then independently meshed. The non-coincident meshes were coupled using the Lagrange Multiplier Method. Joint configurations comprising of different layup sequences were tested virtually. Firstly, to determine if expected tow-matrix interactions were captured through use of Lagrangian constraints and to further provide an indication of their relative performance ranking. Finally, the mechanical performance of the metal-composite hybrid structure was assessed.