Abstract An isogrid is a lattice structure with a high strength to weight ratio making it an ideal structure for spacecraft. Isogrids were originally designed to yield isotropic properties; however, recent finite element analyses show that isogrids do not exhibit isotropic behavior. Isogrids are theorized to be isotropic because of the equal distribution of stresses induced by the structure’s geometry. To determine the isotropy of an isogrid, truss and finite element analyses are executed to predict failure among four various isogrid specimens. The isogrid specimens are 3D printed and vary in geometry to determine the effect of geometric parameters on the isotropy of the structure. In addition, experimental tests are conducted by applying compressive loads to the specimens using a universal testing machine (UTM) with digital image correlation (DIC) to measure strain. The analyses indicate that isogrids are not isotropic because of the observed unequal load distributions.
Highlights Analytical, FEM, and experimental assessment of isogrid structures. Isotropy assumption for isogrids is demonstrated to be incorrect. Four different isogrid sizes tested using 3D printed specimens with DIC. All techniques indicate that the diagonal stiffeners carry a higher stress than the horizontal stiffeners.
Examination of isotropy assumption in isogrid structures through analysis and experimentation on four isogrid variations
Acta Astronautica ; 202 ; 422-432
2022-10-23
11 pages
Article (Journal)
Electronic Resource
English
AIAA | 1975
|NTRS | 1975
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