不同温度下的柏木构件顺纹压缩损伤规律研究  

Study on Compression Damage Law of Cypress Under Different Temperatures

作　　者：李猛 佘艳华[1] 贺才豪 何佳明 陈迪 Li Meng;She Yanhua;He Caihao;He Jiaming;Chen Di(School of Urban Construction,Yantze University,Jingzhou Hubei 434023,China)

机构地区：[1]长江大学城市建设学院,湖北荆州434023

出　　处：《西南林业大学学报（自然科学）》2023年第5期153-163,共11页Journal of Southwest Forestry University：Natural Sciences

基　　金：国家自然科学基金项目(51408075)资助;住房和城乡建设部科技项目(2021-K-0860)资助。

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,本试验以绝干后的柏木构件为研究对象,利用声发射技术和数字图像系统进行原位检测。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,探究不同温度下木材裂纹的萌生规律以及起裂荷载。结果表明:在120、140、160、180℃温度下的柏木构件极限均荷载下降幅度分别为16.2%、6.8%、66.4%;结合声发射参数数据对应的荷载值与DIC损伤云图可以分析木构件在初始破坏阶段的起裂荷载分别为125、62、40、32 kN。可见,温度越高木材极限荷载和起裂荷载越低,温度对木材力学退化性能影响明显。In order to accurately determine the crack initiation law of wood component duringdamage and fracture and effectively evaluate the degree of wood damage,in this experiment,cypress components under different temperature environments were taken as the research object.It was used to in-situ detect the compression damage evolution of cypress components at different temperature by acoustic emission techonlogy and digital image system.By analyzing the change of acoustic emission parameters and the strain curve of the crack surface area,the crack initiation law and crack initiation load of wood at different temperatures were explored.The results showed that the decrease in ultimate mean load of cypress members at 120,140,160 and 180℃were 16.2%,6.8%and 66.4%,respectively;the load value corresponding to the acoustic emission parameter data and the DIC damage cloud diagram can be used to analyze that the crack initiation load of cypress component at the crack initiation stage is 125,62,40 and 32 kN respectively.It was show that the higher the temperature,the lower the ultimate load and cracking load of wood,and the temperature has significant effect on the mechanical degradation performance of wood.

关 键 词：木构件 高温 声发射 数字图像相关法 起裂荷载 

分 类 号：S781[农业科学—木材科学与技术]