【摘要】 本文采用超声脉冲首波等幅法测试了红松(Pinus koraiensis)、兴安落叶松(Lerix dahurica)、水曲柳(Fraxinus mandshurica)和紫椴(Trlia amurenis)四种无疵气干材的顺纹和横纹超声速度及超声弹性模量,并用一元和二元回归分析了这两种超声参数与木材顺纹抗压强度和抗弯强度的相关性。结果表明: 1.轴向超声弹性模量与顺纹抗压强度、抗弯强度的相关紧密,相关方程可用一元线性函数或幂函数表示。 2.以轴向超声速度和木材密度为变量与顺纹抗压强度或抗弯强度建立的二元线性或幂函数相关方程,其相关程度较一元回归更为紧密,累计误差也有所减小。 3.幂函数与线性函数的相关系数(r)大致相等。 4.横向超声参数与顺纹抗压强度的相关显著,而与抗弯强度的相关不显著。 5.采用“首波等幅法”可对2×2×3cm的标准试样进行有效的检测,解决了小试样不易测试的问题。更多还原

【Abstract】 By means of ultrasonic pulse, we checked the longitudinal and horizonatal ultrasonic velocity and ultrasonic modulus of elasticity of four species of wood, they are Pinus koraiensis, Larix dahurica,Faxinus mandshurica and Tilia amurensis, which are air dried.Correlativity between two ultrasonic parameter and the longitudinal compressive strength and bending strength of wood has been analyzed with monodic and dualistic regression. The results showed that:(1) The correlativity between the longitudinal compressive strength and bending strength of wood is very close, whose correlative equation can be explained by monodic linear function y=ax+b or power faction y=ax~b.(2) We have also set up the dualistic linear or power function correlative equation between longitudinal ultrasonic velocity, density of wood, whose correlative degree is much closer than the correlative degree of monodic linear fuction. Its accumulative total error has also decreased.(3) The correlative coefficiency(r)between power fuction and linear fuction is almost same.(4) The corrclativity between the horizonatal ultrasonic parameter and longitudinal compressive strength is obvious, but the correlativity between the horizonatal ultrasonic parameter and longitudinal bending strength is not obvious.(5) We adopted the new method, which is named "equal spoke of first wave" and checked 2×2×3cm standard samples successfully, so it is possible to check the little samples.更多还原