Mohammad shishesaz - Professor, Shahid Chamran University, Ahwaz, Iran
Mohammad Mahdi Attar - Ph.D Student, Azad Islamic University, Science and Research Branch

The objective of this paper is to investigate the effects of geometric parameters such as, edge distance to pin diameter ratio e/d, pins center to center distance, and size of each pin hole on stress distribution in a unidirectional composite laminate subjected to a tensile load at infinity. The solution is obtained analytically as well as numerically, using finite element technique. It is assumed that all long and short fibers (cut between any two successive pin holes) lie in a finite width laminate. The analytical solution is obtained using shear-lag theory. The resulting pin loads on composite plate are modeled through a series of spring elements accounting for pin elasticity. The analytical results on stress concentration factors were compared to those of finite element values. A close match is observed between the two methods. Also the effect of two pins in series is examined on stress distribution in the laminate.

Composite material, stress concentration,shear-lag theory, serial pins