Fatigue performance and parameter optimization of CFRP-reinforced steel plate considering elevated temperature

This article aims to investigate the effect of elevated temperature on the fatigue performance of CFRP-reinforced cracked steel plates and optimize the design parameters for their reinforcement. Based on the self-developed adhesive GY34, a finite element model of the CFRP-reinforced central cracked steel plate is established by the ABAQUS software. Parametric analysis is carried out on different bonding methods of CFRP plates and different thicknesses of adhesive layers for CFRP-reinforced cracked steel plates. The effect of elevated temperature on the reinforcement is also studied to verify the excellent performance of GY34 adhesive. Furthermore, the enhancement of fatigue life for cracked steel plates reinforced with CFRP plates at different temperatures is investigated using the Paris model and modified Newman model. The results show that double-sided reinforcement with CFRP is more effective than single-sided reinforcement. All of the different bonding methods could reduce effectively the stress intensity factor of cracked steel plates and improve significantly the bearing capacity of the steel plates. Among them, increasing the number of CFRP layers and their elastic modulus yield the most significant improvement on the reinforcing effect. Elevated temperatures effect greatly on the mechanical properties of adhesively bonded CFRP-reinforced steel plates. The effective bonding length and the stress intensity factor amplitude at the crack tip of the steel plate increases with temperature rises, which may accelerate the growth rate of fatigue crack and reduce the reinforcing effect on fatigue life.