This paper deals with two main problems in laminate design: the search for
uncoupled and quasi-homogeneous laminates. Using the polar representation m
ethod, the authors show the existence of a particular class of mathematical
ly exact solutions to these two problems. An important feature of these sol
utions is that they are independent of the orientations of the layers. In f
act. these orientations are not fixed by the method, and each solution dete
rmines in reality only a stacking sequence. where each layer belongs to a g
roup of plies having the same orientation. The orientations remain undeterm
ined, and it is up to the designer to fix them. In any event, whether the l
aminate is uncoupled or quasi-homogeneous. the orientations of the layers w
ill reamin free. and this is a true advantage for an optimisation procedure
when supplementary conditions are required The characteristics of the solu
tions and the general results found by the authors are discussed in the pap
er, which concludes with some numerical examples. (C) 2001 Published by Els
evier Science Ltd. All rights reserved.