Laser fabricated metallic cellular sandwich panels

Abstract

Corrugated core sandwich panels comprise a corrugation sheet between two thin face sheets. The significant features of such panels are their high strength and stiffness to weight ratios; however, the stiffness is substantially less perpendicular to their direction of corrugation than in the parallel direction. In this paper, the application of a carbon dioxide laser to fabricate a different type of metallic sandwich panel, a closed cellular sandwich panel, is presented. This sandwich panel comprises an orthogonal grid of mechanically interlocked stiffeners between two thin face sheets. Its strength and stiffness to weight ratios are high; however, its stiffness in two orthogonal directions can be made equal. The stiffeners of the cellular sandwich panels are laser cut and autogenously welded to the face sheets at high speeds without significant distortion to form panels with beneficial prestressing. Details of the fabrication method and results of a preliminary stress analysis and mechanical tests are reported.Corrugated core sandwich panels comprise a corrugation sheet between two thin face sheets. The significant features of such panels are their high strength and stiffness to weight ratios; however, the stiffness is substantially less perpendicular to their direction of corrugation than in the parallel direction. In this paper, the application of a carbon dioxide laser to fabricate a different type of metallic sandwich panel, a closed cellular sandwich panel, is presented. This sandwich panel comprises an orthogonal grid of mechanically interlocked stiffeners between two thin face sheets. Its strength and stiffness to weight ratios are high; however, its stiffness in two orthogonal directions can be made equal. The stiffeners of the cellular sandwich panels are laser cut and autogenously welded to the face sheets at high speeds without significant distortion to form panels with beneficial prestressing. Details of the fabrication method and results of a preliminary stress analysis and mechanical tests are rep...