树木内部应力波传播速度模型

A stress wave propagation velocity model of standing trees

为了提高应力波技术在活立木无损检测应用领域的可行性,分析了应力波在健康树木中的传播规律,并建立了应力波传播速度数学模型。针对银杏Ginkgo biloba等不同树种的健康树木进行了多组实验,并利用树木断层成像技术对提出的应力波传播速度模型进行验证。结果表明:在健康树木中,方向角θ与传播方向速度vT和径向速度vR比值之间的关系为vT/vR≈-0.2θ2+1,与所提出的理论模型吻合,方向角θ与应力波传播速度之间的线性回归模型拟合度较高,决定系数高于0.95。提出的应力波传播速度模型不受树种变化影响。

To improve the feasibility of nondestructive stress wave testing of standing trees, stress wave propa- gation in healthy trees was analyzed using linear regression analysis and a mathematical model of the stress wave propagation velocity was established. Several experiments were carried out for healthy trees of different species, and simultaneously the tomogram imaging technology was used to validate the proposed propagation velocity model of the stress wave. Experimental results of healthy trees showed that the linear regression rela- tionship between the direction angle 0, the velocity （VT） for the propagation direction, and the radial velocity （vR） could be expressed as VT/VR≈-0.2 θ2 ＋ 1, and the coefficient of determination R2〉0.95, which demon- strated that the proposed mathematical model was correct.