摘要
为准确判定木构件损伤断裂时裂纹萌生规律,有效评估木材损伤程度,该文以含水率0%、20%、40%、60%的杉木为研究对象,基于声发射(Acoustic Emission,AE)技术和数字图像相关(Digital Image Correlation,DIC)技术对不同含水率试件的损伤过程进行原位检测,通过分析声发射参数变化和裂纹表面区域应变曲线变化特征,探究不同含水率下木材裂纹的萌生规律以及起裂荷载。结果表明,木材内部损伤程度可基于声发射累计振铃计数和振幅反映,DIC能够实时检测木材表面裂纹尖端区域的应变变化,根据应变特征变化可有效判断裂纹萌生与扩展;通过建立木材裂纹萌生、扩展行为与声发射和表面应变关系,能够准确确定起裂荷载。试验结果可为研究具有不同物理性能的木材损伤机理提供理论依据。
In order to accurately determine the crack initiation law during the damage and fracture of wood components and effectively evaluate the degree of wood damage,in this experiment,Chinese Fir with moisture content of 0%,20%,40%and 60%is taken as the research object.Based on acoustic emission(AE)technology and digital image correlation(DIC)technology,the damage process of specimens with different moisture content is detected in situ.By analyzing the changes of acoustic emission parameters and the change characteristics of strain curve in the crack surface area,the initiation law and crack initiation load of wood cracks under different moisture content are explored.The results show that the internal damage degree of wood can be reflected based on the cumulative ringing count and amplitude of acoustic emission.DIC can detect the strain change at the tip of wood surface crack in real time,and can effectively judge the crack initiation and propagation according to the change of strain characteristics.The crack initiation load can be accurately determined by establishing the relationship between crack initiation,propagation behavior,acoustic emission and surface strain.The experimental results can provide a theoretical basis for studying the damage mechanism of wood with different physical properties.
作者
李猛
陈迪
田康
何佳明
佘艳华
LI Meng;CHEN Di;TIAN Kang;HE Jiaming;SHE Yanhua(School of Urban Construction,Yangtze University,Jingzhou 434023,China)
出处
《森林工程》
北大核心
2022年第4期69-81,共13页
Forest Engineering
基金
国家自然科学基金项目(51408057)
住房和城乡建设部科学技术项目(2021-K-0860)。
关键词
木构件
含水率
声发射
数字图像相关法
表面应变
起裂荷载
Wood member
water content
acoustic emission
digital image correlation
surface strain
crack initiation load
