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A.1 Preliminary Calculation of the Honeycomb plate using finite element Analysis

A.1.5 Results of the calculations


Stress results
The stresses in the honeycomb plate for each load case are shown in Figures A-8 to A-13. Figures A-8 to A-10 present the Von Mises stresses due to the three load cases in the aluminum skins + frame and triangle, while Figures A-11 to A-13 present the Von Mises stresses due to the three load cases in the honeycomb core.

The maximum stresses appear for LOAD CASE 3 (i.e. 4.25 g on X, 4.25 g on Y, and 17 g on Z). The maximum values for the Von Mises stresses are the following for all layers of the composite structure:
Maximum Von Mises stresses
 Aluminum skin+frame and triagleAluminum core
Load case 117.5 MPa0.069 MPa
Load case 212.6 MPa0.05 MPa
Load case 341.8 MPa0.207 MPa

Displacement results
The displacements for the honeycomb plate are shown in Figures A-14 to A-16. Different colors on these figures illustrate different displacements of the nodes from their original undeformed positions. The maximum displacements appear, of course, in the central region of the plate where the load cases are applied.
Maximum displacement results
 Global displacement maximum value
Load case 10.41 mm
Locad case 20.40 mm
Locad case 31.6 mm

Discussion
Considering the worse load case, i.e. load case 3, we have the maximum stress on the skins equal to 42 MPa, which multiplied by a safety factor of two gives 84 MPa. The margin of safety is 4.23. Concerning the aluminum core, we have the maximum stress for load case 3 equal to 0.2 MPa, which gives 0.4 MPa including the safety factor of two. The margin of safety is then equal to 4.75.


Issue: Draft - Revision: 04 - Last Modified: 20 April 1997