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From the 1997 sandwich paper.
One or more of these special design margins, present only when sandwich panels and shells are being optimized by PANDA2, may constrain the evolution of the design of a panel or shell with sandwich wall construction during optimization cycles.
Explanation of some terms used in this table:
"strng" means stringer/shell wall module
M = number of axial half-waves between adjacent rings (if there are any rings, otherwise number of axial halfwaves over the length of the panel or shell).
N = number of circumferential half-waves between adjacent stringers.
"VINSON" means face sheet wrinkling according to Vinson's theory.
"HOFF" means face sheet wrinkling according to Hoff's theory.
"dimpling" means buckling of face sheet over the diameter of a single honeycomb cell, with M and N being the number of axial and circumferential halfwaves over that diameter.
"face1/celldiam" is a margin based on a constraint that the wrinkling half-wavelength of one of the face sheets shall be greater than k times the honeycomb cell diameter, where k is provided by the PANDA2 user.
"face2/celldiam" is the same as "face1/celldiam" except it pertains to the other face sheet of the sandwich wall.
"localbuck" means buckling of the entire sandwich wall between adjacent stiffeners (if any): the first failure mode shown 4 slides ago.
"corecrimp" means crimping of the core, one of the sandwich wall failure modes shown 4 slides ago.
"Core crushing" is one of the sandwich wall failure modes shown 4 slides ago.
"sandwichcore tension" means sandwich wall failure due to excessive tensile stress in the core.
"L-dir" and "W-dir" sandwich core shear mean failure in the "Length" and "Width" directions due to excessive transverse shear in the core, one of the failure modes shown 4 slides ago.
"face sheet pull-off" means failure of the glued interface between face sheet and core.
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