Novel design of foam core junctions in sandwich panels

An improved design of core junctions in sandwich panels/beams is proposed. The improved/novel design consists of a specific geometrical shaping of the boundary of the adjoined core materials, which substantially diminishes the local stress concentrations at core junctions subjected to transverse shear loading. Two groups of the beams with conventional butt junctions and modified (spline shaped) junctions are manufactured and tested under fatigue loading conditions. A rigorous statistical treatment of the experimental data shows that sandwich beams with modified core junctions display significantly higher fatigue performance than sandwich beams with conventional “butt” core junctions.