Title:
Lap Splice Length and Fatigue Performance of
Fiber-Reinforced Polymer Laminates
Author(s):
Xinbao Yang and Antonio Nanni
Publication:
Materials Journal
Volume:
99
Issue:
4
Appears on pages(s):
386-392
Keywords:
fatigue; lap splice; reinforcement; stiffness; strength; tensile strength
DOI:
10.14359/12221
Date:
7/1/2002
Abstract:
In this study, the lap splice length and the long-term (fatigue) performances of lap-spliced carbon FRP (CFRP) laminates were investigated. Lap-spliced CFRP coupon specimens were fabricated with splice lengths of 12.7, 25.4, 38.1, 50.8, 76.2, and 101.6 mm. To eliminate the bending on the lap splice joint, a symmetric specimen configuration was adopted. The width of the specimens was 38.1 mm. These specimens were tested to failure under tension. The ultimate load, failure mode, and strain distribution on the surface of both the nonlapped and lapped areas were monitored. It was found that a length of 38.1 mm was sufficient to develop the static ultimate strength of the CFRP laminate. Tension-tension fatigue tests were performed on 101.6 mm lap-spliced specimens to investigate the long-term performance. A stress ratio-versus-number of cycles curve was constructed using the test data and was compared with the theoretical results. It was shown that 101.6 mm lap-spliced CFRP laminates can sustain more than 2.0 million load cycles with no effect on residual strength, if the maximum applied stress does not exceed 40% of the ultimate static strength. A 101.6 mm lap splice length is recommended for field use as currently adopted in standard practice.