摘要
基于应力波的检测方法是一项相对成熟的无损伤质量评估技术。该技术在木材质量检测领域被广泛的应用,并已逐步扩展到活立木的野外测量当中,用以更为有效的提高木材利用率。在我国东北林区,野外采伐工作在冬季持续作业,此时树木正处于冻结状态。而应力波技术在冻结活立木质量检测方面的研究还鲜有报导,这也为低温下应用应力波技术进行木材质量检测与评估的准确度提出了疑问。因此,为了解应力波在冻结活立木中的传播情况,本文通过试验方法,选择哈尔滨林业示范基地10个东北地区常见的主要树种,在冬季-10℃以下进行应力波在活立木中传播速度的测试以作为基础研究。试验结果显示,冻结状态下应力波在十个活立木树种中的纵向传播速度总体平均在4 187 m/s,径向传播总体速度的平均值为2 013 m/s。冻结状态活立木中的含水率与应力波纵向传播速之间存在显著的负相关关系,相关系数多数在0.8以上。测得的径向传播速度受含水率的影响不是十分显著。
Nondestructive testing technique based on stress wave is a relatively mature method for wood quality assessment,which has been widely applied in the area of wood quality evaluation and increasingly used for field measurements of standing trees to enhance the effective utilization of wood.For the forests located in north China,the field operation and wood products processing all keep going at low temperature in winter when the standing trees are frozen.However,the research on the application of stress wave testing technique to measure frozen standing tree is rarely reported recently.Thus,the accuracy of assessment is questioned when stress wave testing technique is used to evaluate the wood quality at subzero temperature.Therefore,the measurements of stress wave propagation velocities（SWPV）in frozen standing trees were conducted as a basic research measure to investigate the law of the stress wave propagation in frozen wood.10 main species of northeast forests in China from Harbin Forest Experimental Station were used to conduct SWPV measurements in winter at-10oC below.The experimental results showed that the overall average values of longitudinal and radial SWPV in frozen standing tees were 4187m/s and 2013m/s,respectively.A negative correlation relationship was found between the longitudinal SWPV and moisture content（MC）of trees with correlation coefficients mostly over 0.8,but the effect of moisture content on the radial propagation velocity is not obvious in frozen wood.
出处
《森林工程》
2013年第4期47-52,共6页
Forest Engineering
基金
中央高校基本科研业务费专项资金资助(DL12BB31)
关键词
应力波
活立木
冻结状态
传播速度
含水率
stress wave
standing tree
frozen state
propagation velocity
moisture content
作者简介
高珊（1980-），女，黑龙江齐齐哈尔人，博士，讲师。研究方向：木材无损检测。
通讯作者：王立海（1960-），男，黑龙江哈尔滨人，博士，教授。研究方向：林业工程。
