Isogrid
From Wikipedia, the free encyclopedia
An isogrid is a structure which has a sheet of material (usually metal) with integral metal stiffeners in a triangular pattern on one side. Isogrids are fabricated by machining material away from a thick sheet or plate of metal, leaving a continuous flat surface on one side and a series of triangular pockets with thicker integral stiffeners between the pockets on the other.
The isogrid structure is effective as a self-stiffened structure where both overall stiffness and strength are important, such as in space launch vehicle rocket structures where the bottom stages of a rocket have to support the full weight of upper stages and payloads.
The name isogrid is derived from isotropic - where a material has equal properties measured in any direction, and grid, referring to the sheet and stiffeners structure. The triangular pattern used in isogrids gives the most even isotropic behavior.
Some space launch vehicles which use isogrid structures include:
The Space Shuttle lightweight and superlightweight external tanks utilize an integrally machined stringer system which is not a true isogrid, though it is somewhat similar. Since the structure is arainged at right angles rather than with triangular bracing it is technically not an isogrid.
