PECULIAR BEHAVIOR OF THE POISSON'S RATIO OF LAMINATED FIBROUS COMPOSITES.

The effective Poisson's ratio of laminated fibrous composites shows a peculiar behavior as it becomes larger than unity or less than zero. This behavior can be utilized in the design of composite structures with special functions. The lamination theory, non-linear programming technique and a heuristic approach are used to find the lay-ups of the laminates with the maximum, zero and the angle-ply symmetric laminates yield the maximum value and unbalanced bidirectional symmetric laminates yield the minimum value. Experimental results show a good agreement with the analytical results.