浙江农林大学学报2017，Vol.34Issue(5)：926-933,8.DOI:10.11833/j.issn.2095-0756.2017.05.021
应力波在树木不同角度纵截面的传播速度模型
Stress wave propagation velocity model for different angles in a longitudinal section of standing trees
摘要
Abstract
To establish a propagation velocity model of stress wave in longitudinal section, standing trees of dif-ferent species were selected as samples to study their stress wave velocity pattern for different angles in the longitudinal section of wood. Using a theoretical analysis, the velocity model of stress waves in the longitudinal section of wood was built. Then within the Zhejiang A & F University Botanical Gardens, a total of 40 test samples from four species of trees was selected. The experimental ArborSonic 3D stress wave imaging system was used with a comparative analysis of the results to determine the stress wave propagation velocity. Analysis of the model included fitting an equation to a healthy sample and a regression analysis. Results showed that the propagation velocity between any two points in the same section increases with increasing direction angle. And the propagation velocity between any two points in different longitudinal sections is related to the angle between the longitudinal section and the diameter section. Healthy sample test data were fitted to: v(θ,α)/v0≈ kx2+ 1 (0 ≤ k ≤ 1) where k was dependent on the size of angle α between the longitudinal section and the radial section of the tree under test. In the established regression model the R2>0.93 indicated that the model had a high goodness of fit. For different species, due to different internal characteristics, stress wave velocities also differed. The propagation law of stress wave in longitudinal section is related to the direction angle θ and α. θdetermines the velocity, andαdetermines the velocity change, which means the size of the quadratic coefficient k of the fitting equation. For the longitudinal section of healthy trees, θ and α and v(θ,α)/v0 satisfied the geo-metric relationships: f(θ, α) = 1 + {[vl-(-0.2α2+ 1)vR] / vl}·θ2. Overall, detection results of different species showed the validity of the model which could have important practical applications for nondestructive testing of wood. [Ch, 5 fig. 5 tab. 17 ref.]关键词
木材科学与技术/应力波/纵截面/传播速度/无损检测Key words
wood science and technology/stress wave/a longitudinal section/propagation velocity/non-de-structive testing分类
农业科技引用本文复制引用
张春晓,冯海林,李光辉,王燕凤,杜晓晨..应力波在树木不同角度纵截面的传播速度模型[J].浙江农林大学学报,2017,34(5):926-933,8.基金项目
国家自然科学基金资助项目(61272313, 61302185, 61472368) （61272313, 61302185, 61472368）
浙江省自然科学基金资助项目(LY15F020034) （LY15F020034）
浙江省新苗人才计划项目(2015R412048) （2015R412048）
