Ultem(R)ate Bracket B2 (0.023 lbs, 0.481 cu in)

grabcad

The lightweight one-piece bracket weighs merely 0.023 lbs and has a volume of 0.481 cubic inches. It is an advanced version of the Ultem(R)ate Bracket B1, which utilizes common 3D printing features to reduce the mass of unstressed but thick parts (bosses). The stress levels are less than 4500 psi, and the singularity/stress riser caused by bolt-bracket contact is calculated analytically to determine correct contact pressure and Hertzian stresses. No optimization is needed as preliminary sizing is done using basic mechanical theory and verified through FEM. The bracket can be printed without supports and features an elastic hinge that enables aligning the two halves during launch vehicle mounting, with enough space for tools to access the bolts. Infill density in unstressed areas is reduced by 15% for further mass reduction. An extra load case considers a 14.7 psi differential pressure inside the infill volume to prevent bracket breakage during ascent. All details about calculations and design considerations are available in the attached PDF file. To depict stress distribution differences, a picture is included, showcasing stresses in a bracket with real contact between bolt and bracket on the left and bonded contact on the right. Kind regards, Wilbert Engels