Product Code: ICAL06_306

Beneficial Pre-Stress in Laser Fabricated, Metallic, Square, Cellular Sandwich Panels
Authors:
Eduard Ventsel, Engineering Science & Mechanics Department, The Pennsylvania State University; State College PA USA
Peter Vigna, Engineering Science & Mechanics Department, The Pennsylvania State University; State College PA USA
Stephen Copley, ARL, The Pennsylvania State University; State College PA USA
Presented at ICALEO 2006

The fabrication of flat, lightweight, stiff, strong, metallic, square cellular sandwich panels, LASCELLTM (Patent Pending), employing laser cutting and stake welding has been applied to the fabrication of large, watertight door panels and frames in a collaborative program with the Naval Surface Weapons Center Carderock Division- Ship Systems Engineering Station and Northrop Grumman Corporation, Newport News. Using a restraining fixture, remarkably flat panels and frames have been fabricated with beneficial pre-stress due to residual thermal strains from welding that increases their resistance to failure from the observed failure mode in bending, localized face sheet buckling on the compression side. The development of the pre-stress has been measured at various stages of the welding process with resistance strain gages fastened to the face sheets. A preliminary linear optimization analysis of square cellular sandwich panels incorporating the beneficial pre-stress has been completed. Details of the fabrication, pre-stress measurements and optimization analysis will be presented.