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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。
In this paper, the first wave amplitude method of ultrasonic pulse was used to test the grain morphology of four unqualified air-dried materials, Pinus koraiensis, Lerix dahurica, Fraxinus mandshurica and Trilia amurenis. And horizontal stripes ultrasonic velocity and ultrasonic elastic modulus. The correlation between the two ultrasonic parameters and the compressive strength and flexural strength of the wood was analyzed by one-element and two-element regression. The results show that: 1. The axial elastic modulus is closely related to the compressive strength and flexural strength, and the correlation equation can be expressed by a linear function or a power function. The binary linear or power function equation established by the axial ultrasonic velocity and wood density as variables and the compressive strength or flexural strength of the parallel grain is more closely related than the one-dimensional regression, and the cumulative error also decreases. 3. Power function and linear function of the correlation coefficient (r) is roughly equal. The transverse ultrasonic parameters have significant correlation with the compressive strength of the parallel grain, but not significant with the bending strength. 5. The “first wave equal amplitude method” can be 2 × 2 × 3cm standard samples for effective testing to solve the problem of small sample is not easy to test.