摘要
为研究碳纤维增强树脂基复合材料(Carbon fiber reinforced polymer,CFRP)加固木柱的轴压损伤性能及破坏机制,对6组不同CFRP缠绕方式的木柱开展了轴向压缩试验并进行了实时声发射(Acoustic emission,AE)监测。分析了不同缠绕层数和不同缠绕角度对CFRP加固木柱破坏形式、力学性能、吸能性能和声发射参数演化规律的影响。结果表明:CFRP的加固能明显改善木材的力学性能,抑制脆性破坏的发生;随着缠绕层数、角度的增大,木柱的极限承载力从112.63 kN提升至161.21 kN,位移延性系数也从1.44提升至1.72;CFRP缠绕层数、角度的增加能够显著提高CFRP加固木柱在轴压损伤过程中的稳定性和吸能能力;根据声发射的振铃计数演化特征可以将CFRP加固木柱的损伤过程分为弹性、压缩屈服和损伤破坏3个阶段;随着缠绕层数、角度的增加,声发射峰值频率逐渐从低频区间(0~80 kHz)向高频区间(160~240 kHz)过渡,损伤形式从大尺度损伤转变为小尺度损伤;不同缠绕方式的木柱声发射能量概率密度均遵循幂律无尺度分布,6种加固方式下,临界指数分别为1.31、1.33、1.36、1.43、1.49、1.57;临界指数随着缠绕层数、角度的增大而增大,CFRP的加固限制了木材内部裂纹的发展,减弱了内部结构的劣化。
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.
作者
黄俊杰
佘艳华
张鹤凡
何佳明
HUANG Junjie;SHE Yanhua;ZHANG Hefan;HE Jiaming(School of Urban Construction,Yangtze University,Jingzhou 434023,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2024年第9期5110-5124,共15页
Acta Materiae Compositae Sinica
基金
国家自然科学基金(51408057)
住房与城乡建设部科学技术项目(2021-K-086)
长江大学创新训练项目(Yz2023008)。
