It has been noted in the literature that polymer-matrix composite laminates
containing thick blocks of like-oriented plies may exhibit matrix cracking
due only to thermal loads during cooldown from autoclave temperatures. In
the study of geometrically scaled laminates, matrix cracking is of particul
ar interest. While smaller coupons with fewer blocked plies may not crack d
ue to thermal loads only, larger coupons of scaled dimensions may. This occ
urs even though all sizes of coupons experience the same thermal cycle.
The present paper addresses the issue of first-ply failure of geometrically
scaled laminated composites. First-ply failure data for a [0(n)/90(n)/0(n)
](T) laminate where n = 1 - 6, are compared to a model incorporating therma
l strains. A good agreement is found between analytical and experimental re
sults. Matrix failure of larger specimens (in the absence of mechanical loa
ds) is predicted.