Ultem(R)ate Bracket B1 (0.028 lbs, 0.578 cu in)

grabcad

This ultralightweight bracket is a one-piece design weighing just 0.028 lbs and occupying a volume of 0.578 cubic inches. It features two mirrored parts connected via an elastic hinge through a bridge. The mass reduction in unstressed but thick parts (bosses) is achieved by utilizing common 3D printing techniques. All stresses are under 4,500 psi, with potential singularity/stress riser from bolt-bracket contact calculated analytically for correct contact pressure and Hertzian stresses. No optimization was needed as preliminary sizing was done using basic mechanical theory, verified through FEM. The bracket can be printed without supports and allows tool access to bolts. Infill density in unstressed areas is 15% lowering mass further. Extra load case considers a 14.7 psi differential pressure inside the infill volume during ascent. Further details are available in the attached PDF file, which also includes stress distribution pictures illustrating contact types between brackets and bolts (October 18, 2016).