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为研究利用纵向振动法测试落叶松锯材动态弹性模量,探究动态弹性模量分布规律,评价落叶松的力学性能。以纵向振动法测试尺寸为4000mm×150mm×50mm和4000mm×100mm×50mm的兴安落叶松锯材A和B的动态弹性模量,对动态弹性模量测试结果进行三参数Weibull分布、正态分布、对数正态分布拟合检验,抽样测试锯材静态弹性模量,并评价锯材的力学性能。结果表明纵向振动法测试的落叶松动态弹性模量和静态弹性模量在0.01水平线性相关;经检验锯材A和B的尺寸对动态弹性模量无显著影响,锯材A和B的动态弹性模量平均值为15475MPa和15347MPa;落叶松锯材A和B的动态弹性模量都符合正态分布;锯材A和B的静态弹性模量设计值分别为15174MPa和15073MPa。验证了落叶松动态弹性模量和静态弹性模量具有相关性,可以利用纵向振动法并根据公式E_(静态)=0.7866E_(FFT)+3.002(R~2=0.8474)估计锯材的静态弹性模量并评价其力学性能;截面尺寸对落叶松锯材的动态弹性模量无影响;可以利用正态分布拟合落叶松的动态弹性模量且其准确性高于Weibull分布;本批次落叶松静态弹性模量达到北美地区进口2550Fb-2.1E等级规格材对弹性模量的要求。
In order to study the dynamic elastic modulus of larch by using longitudinal vibration method, the distribution law of dynamic elastic modulus was explored to evaluate the mechanical properties of larch. The dynamic elastic modulus of Larix chrysanthemum larch with the size of 4000mm × 150mm × 50mm and 4000mm × 100mm × 50mm was tested by longitudinal vibration method. The three-parameter Weibull distribution, normal distribution, Logarithmic normal distribution fitting test, Sampling Saw static modulus of elasticity, and evaluate the mechanical properties of sawn timber. The results show that the dynamic modulus of elasticity of larch and the static elastic modulus of the longitudinal vibration test are linearly correlated at the 0.01 level. The tested sizes of sawn timber A and B have no significant effect on the dynamic elastic modulus. The dynamic elasticity of the sawn timber A and B Modulus average of 15475MPa and 15347MPa. The dynamic elastic modulus of larch sawn timber A and B all fit normal distribution. The static elastic modulus of sawn timber A and B are 15174MPa and 15073MPa, respectively. It is verified that the dynamic modulus of elasticity of larch and the static modulus of elasticity are correlated, and the longitudinal elasticity method and the equation E_ (static) = 0.7866E_ (FFT) +3.002 (R ~ 2 = 0.8474) can be used to estimate the static elasticity Modulus and evaluation of mechanical properties; section size has no effect on the dynamic elastic modulus of larch sawn timber; the normal distribution can be used to fit dynamic modulus of larch and its accuracy is higher than the Weibull distribution; the batch deciduous Loose-state elastic modulus reached North America imported 2550Fb-2.1E grade specifications of the elastic modulus requirements.