Mechanical properties balance in novel Z-pinned sandwich panels: Out-of-plane properties

The paper presents the first complete set of test results obtained from quasi-static measurements of the out-of-plane tension, shear and compression properties of novel X-Cor™ and K-Cor™ flat sandwich panels. The cured panels were composed of 0.75-mm-thick quasi-isotropic IM7/8552 skins, separated by 12.7-mm-thick Rohacell® foam core containing 0.51 mm diameter carbon fibre pins (Z-Fiber®), arranged in a truss pattern at pin angle of either 22 or 30° to the vertical. To obtain a suitable baseline comparison, the equivalent set of properties was measured for Nomex honeycomb core panels sandwiched by the same composite skins. The novel Z-pinned cores are found to exhibit higher specific stiffness than conventional sandwich cores, but lower strength.