Abstract:
To study the axial compression damage performance and failure mechanism of wood columns strengthened with carbon fiber reinforced polymer (CFRP), axial compression tests and real-time acoustic emission (AE) monitoring were carried out on six groups of wood columns with different CFRP winding methods. The effects of different winding layers and winding angle on the damage forms, mechanical properties, energy absorption properties and acoustic emission parameters of CFRP-reinforced wood columns were analyzed. The results show that: The reinforcement of CFRP can significantly improve the mechanical properties of wood, inhibit the occurrence of brittle damage; With the increase of the winding layers and angle, the ultimate bearing capacity of the wood columns increases from 112.63 kN to 161.21 kN, and the displacement ductility factor also increases from 1.44 to 1.72; The increase of CFRP winding layers and angle can significantly improve the stability and energy absorption capacity of CFRP-reinforced wood columns in the axial compression damage process; According to the evolution characteristics of acoustic emission ringing count, the damage process of CFRP-reinforced wood columns can be divided into three stages: Elastic stage, compressive yield stage and damage failure stage; With the increase of the winding layers and angle, the peak frequency of acoustic emission gradually transitions from the low-frequency range (0-80 kHz) to the high-frequency range (160-240 kHz), and the damage form changes from large-scale damage to small-scale damage; The probability density of acoustic emission energy of wood columns with different winding methods follows a power-law scale-free distribution, the critical indices under six reinforcement methods are 1.31, 1.33, 1.36, 1.43, 1.49 and 1.57, respectively; The critical index increases with the increase of winding layers and angles, the reinforcement of CFRP limits the development of internal cracks and weakens the deterioration of the internal structure of the wood.