Dilatation and Through-the-Thickness Poisson's Ratio of Composite Laminates

In this paper an investigation of the through-the-thickness Poisson's ratio and the dilatation for a general class of randomly-oriented composite laminate is presented. A simple random statistical analysis has been used to demonstrate that under certain conditions, for instance, a laminate with 40 plies or more, the mean values of the through-the-thickness Poisson's ratio and the dilatation in the randomly-oriented laminate are close to those values evaluated from the analytical formulation. Also, the influence of the various lamina material properties E 2 1E 1 , E31EI, G 12 /EI, v 12 , v 31 and v 32 on the through-the-thickness Poisson's ratio and the dilatation of the laminate are obtained. The results from this statistical analysis provide a set of general guidelines for designing the through-the-thickness Poisson's ratio and the dilatation of the composite laminates to meet various requirements in engineering applications.