TM 1-1500-204-23-11
Where an odd symmetric laminate has additional
plies of the same angle adjacent to the center ply,
a subscript is used with the over line to indicate the
number of half ply on either side of the center plane.
See igure 5-21.
Figure 5-18. Example for Accommodating Larger
Numbers
(6) Symmetric Laminates. Symmetric lami-
nates with an even number of plies still list the plies
in sequence, starting at one face, but stopping at the
plane of symmetry instead of continuing to the other
face. A bracket subscript S indicates only one-half
of the laminate. See igure 5-19.
Figure 5-21. Example Odd Symmetric Laminate
with Multiple Same Angled Plies
(7) Sets. Repeating sequences of plies are
called sets and are enclosed in parenthesis. A set
is coded in accordance with the same rules which
apply to a single ply. See igure 5-22 and igure 5-23.
Laminates are often composed of identical repeated
sets. When it is desired to refer to the laminate in a
generic sense or when the number of sets has yet to
be determined, as in the sizing stages of design, the
coeficient "n" will be used with the bracket subscripts
T and S instead of a numerical coeficient.
Figure 5-19. Example Even Symmetric Laminate
Symmetric laminates with an odd number of plies
are coded the same as even symmetric laminates,
except that the center ply, listed last, is over lined to
indicate that half of it lies on either side of the plane
of symmetry. See igure 5-20.
Figure 5-22. Example Sets for Symmetric
Laminates
Figure 5-20. Example Odd Symmetric Laminate
