Hokiesat Side Panel Analysis Craig Stevens cls@vt.edu 7/12/01

Applied proper loading (moment arm) using reinforced steel shell elements. All loads are component masses * 11G’s in +X, +Y, +Z directions.

Skin Shell Element Stress Distribution 3 2 1

Skin Shell Element Stress Distribution 4 6 5

Isogrid Beam Element Stress Distribution 1 2 3

Isogrid Beam Element Stress Distribution 4 6 5

Panel Test Analysis 1 Boundary Conditions: Fixed the panel edges in panel surface normal direction Fixed 6 center fastener locations in all 3 axes Applied distributed load to beam elements totaling 44 lb

Conclusions: Loads applied normal to the panel surface do not provide the shear stresses on the skin panels that are observed in the launch configuration Applying greater loads to the panel to get the appropriate skin stress magnitudes will most likely damage the structure due to failure of the isogrid webs

Panel Test Analysis 2 Boundary Conditions: Fixed the panel edges in panel surface normal direction Fixed top edge in all 3 axes Applied distributed load to bottom edge totaling 2000 lb

Von Mises Skin Shell Element Stress Distribution

X-Direction Skin Shell Element Stress Distribution

Y-Direction Skin Shell Element Stress Distribution

Conclusions: Loads applied parallel to the panel surface do not provide the normal stresses in the isogrid that are observed in the launch configuration Applying these load magnitudes to the panel is somewhat unreasonable for the personel and schedule involved