Development of fatigue testing procedure for unidirectional carbon fiber composites

Abstract

There is an increase in the use of fiber reinforced polymer materials in the vehicle industry due to the material’s significance in designing lightweight vehicle structures and components. For these structures and components structural mechanical properties are important to characterize, particularly the fatigue properties. An approach on setting up a systematical fatigue testing procedure to find an optimal specimen design for the provided lab environment is proposed. It is found that the tab configuration and tab material have a large impact on the test results. The proposed test procedure results in fatigue failure of the CFRP material rather than tab failure. The final method has resulted in successfully testing parallel-side-coupon specimens under tension-tension fatigue testing, with a load ratio of 0.1 and with a frequency of 5 Hz.