Low cycle fatigue behaviouir of steel/ CFRP composite exposed to loads with constant amplitude.

Abstract

This paper aims to investigate the fatigue performance of CFRP (Carbon Fibre Reinforced Polymer) bonded steel plate under the three point flexural fatigue. CFRP (Carbon Fibre Reinforced Polymer) bonded steel plate subjected to low cycle fatigue (LCF) to estimate and compare fatigue strength gain with respect to un-strength steel structures. Normal modulus (240 GPa) unidirectional CFRPs were used. Two test series were performed in this test series. A constant loads amplitudes cyclic load is applied on specimens with 2 kN magnitudes and 5 Hz frequency. The Coffin-Manson relation was used to explain the theoretical behaviour of LCF cycles. CFRP strengthened steel indicated a significant improvement in the fatigue life. This retrofitting technique reported significant fatigue strength gain; in the range between 26.8 % and 36.52 %.