1063. Isogrid Weight Optimum Structures

Paper

Abstract

Future aerospace missions, vehicles, and payloads, will be increasingly dependent on high-performance, lightweight,
Cost-effective structures. Isogrid rates serious consideration in this regard.
Here we will describe different isogrid configurations, how they apply to shell and panel structures, and, by way of
examples, how cylindrical isogrid shells are analyzed and sized. Design equations and procedures are presented,
comparisons are made between different isogrid configurations, and useful preliminary design data is presented.
Finally, merits of a Space Tug composite isogrid shell are discussed.
Strength and weight are inseparable entities in our treatment of isogrid. We attempt to be analytically comprehensive,
accounting for all reasonable local and general instability modes in which isogrid can fail and not overlooking such
details as fillet radii and machining mismatches in weights equations.
Features of isogrid include: minimum use non-optimum or non-fully-stressed material,low piece-part count especially
when it is machined, good post buckling characteristics (isogrid can experience some modes of local failure without
succumbing to general instability), and a minimal space envelope needed shell applications because isogrid structures
can be designed without dependance on stabilizing frames.