Impact damage testing on composite marine sandwich panels, part 1: Quasi-static indentation

Abstract

High fibre content composite laminate skins use marine grade orthophthalic polyester, POLYLITE® 440-M850 resin and chopped strand mat/woven E-glass for the thin outer face skins and DIVINYCELL® H100 closed-cell linear PVC foam as core. Marine grade hybrid sandwich panels are designed in accordance with BS EN ISO 12215-5:2008 for small craft hull construction, using a wet lay-up and cured under vacuum pressure. Impact damage testing followed ASTM D7766-11 and ASTM D6264-98 procedures A and B for rigidly supported and simply supported sandwich panels. A review of the current state of standard testing procedures of marine sandwich panels is described. Testing using the default hemisphere indentor also included other standard rock geometries – conical, square-based pyramid and flat-faced cylindrical. The damage incurred under each variation of indentation impact is described, in terms of force, absorbed energy and indentation displacement. New contact laws are suggested for the different rock geometries. Destructive sectioning of the panels provides the visual damage incurred through the thin face skins and core and the roles played by all members comprising the sandwich panels.