摘要
为分析应力波在木材中传播的影响因素,研究应力波传播规律,在实验室内,采用Arbotom应力波测试仪测试60个红松无疵小试件在不同含水率(从绝干到饱湿)和不同温度(-30,-20,-10,-5,0,5和20℃)下的应力波传播速度。在此基础上,分别分析应力波传播速度随含水率或温度变化的规律,探讨导致应力波传播速度变化的原因,并建立三者之间的回归模型。结果表明:含水率和温度是影响木材中应力波传播速度的2个重要因素。应力波传播速度随含水率增加或温度升高均呈逐渐下降趋势。在含水率32%(纤维饱和点附近)以下,传播速度随含水率增加下降幅度较大,反之则较小;当含水率低于50%时,传播速度随温度升高呈线性下降趋势;当含水率高于50%时,传播速度在0℃上下有一明显的跳跃。含水率、温度与应力波传播速度之间的二元线性回归模型拟合优度较高,决定系数R2均高于0.95。
To investigate the effects of temperature and moisture content on the propagation velocity of stress wave in wood,we conducted stress wave tests on sixty korean pine（Pinus koraiensis） clear wood specimens at different moisture contents（MC）and temperatures（-30,-20,-10,-5,0,5 and 20 ℃ respectively）in laboratory.Based on this,the relationship between the propagation velocity of stress wave and moisture content or temperature was analyzed respectively,and the regression models among three parameters were built finally.The analysis results indicted that both moisture content and temperature were two important factors for affecting the propagation velocity of stress wave.Stress wave velocity decreased gradually as MC or temperature increased.Stress wave velocity is more significantly affected by moisture content as MC is below the fiber saturation point（FSP）than as MC is above the FSP.When MC was below 50%,stress wave velocity decreased linearly as temperature increased,but stress wave velocity had an abrupt jump near 0 ℃ temperature when MC was above 50%.The binary linear regression models between MC and the propagation velocity of stress wave for specific temperature conditions were found fitting to the experiment data very well（R2 0.95）.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2011年第9期123-128,共6页
Scientia Silvae Sinicae
基金
国家自然科学基金(30671643)
东北林业大学优秀博士学位论文培育计划及研究生创新项目
关键词
应力波
传播速度
温度
含水率
木材
红松
stress waves
propagation velocity
temperature
moisture content
timber
pinus koraiensis
