Shear strength of pultruded composite pins with external confinement

Abstract

Weight reduction using composites has gained increasing attention in recent times. In this study, pultruded composite pins (unconfined and confined) were manufactured and tested by using a custom double shear testing fixture. Different configurations were applied for confinement of the composite pins, including weft-knitted fabrics (plain, 1x1 rib, and Milano), woven fabrics and E-glass 130 tex fibers/adhesive cloth. They were externally wrapped and bonded to the unconfined composite pins. In each case, five identical specimens were tested, and shear strength data were analyzed by using two-parameter Weibull statistics. The results showed that the maximum shear strength took its highest value in the unconfined case for both average values of the test results and for 99% reliability under Weibull distribution. The confinement had a negative effect on the average shear strength of the unconfined pins. It was also seen that the 99% reliability values of shear strength were approximately equivalent to the 0.7 average value of the shear strength.