含水率对山核桃树木材应力波频谱的影响

摘要

Detection was conducted on stress wave of 5 clear and 5 decayed specimen ofCarya cathayensis wood with different moisture content. Variation of detected stress wave spectrum was analyzed. The results showed that moisture content of the wood tested was an important factor affecting the stress wave spectrum. Resonant frequency of the stress wave decreased gradually with the increase of moisture content, and greatly with the moisture content below fiber saturation point. The regression model between stress wave spectrum and moisture content was established. The linear regression model between moisture content of the tested wood with resonant frequency in stress wave had high goodness of fit. The correlation coefficient (R2) was higher than 0.93.%对5组山核桃（Carya cathayensis）木材健康试样和5组腐朽试样在不同含水率下的应力波频谱进行测试，分析应力波频谱中共振频率随含水率的变化规律。结果表明：含水率是影响木材中应力波频谱的重要因素，应力波频谱中的共振频率随含水率的增加呈逐渐下降趋势，在含水率低于纤维饱和点时，应力波频谱中共振频率随含水率下降幅度相对较大，反之则较小，且对高频部分共振频率的影响比低频部分共振频率较大；健康和腐巧两种试材含水率与应力波频谱中共振频率之间的线性回归模型拟合优度较高，相关系数R2均高于0.93。