木材顺纹抗剪强度测试方法的改进

A New Test Method for Shear Strength Parallel to Wood Grain

在测量小径材或薄板抗剪强度时,常由于材料尺寸过小,无法按国标规定制作试样。本文提出了一个木材顺纹抗剪强度测试方法的改进方案,即在基本保持试样原有力学性状不变的前提下,将剪切试样的宽度缩小为国家标准试样的一半,并通过杉木和I-214杨的标准试样和改进试样的对比试验,论证了改进方案的可行性。对比试验表明:改进试样和标准试样的抗剪强度差异不显著(0.05水平),二者强度平均值相对差异的绝对值低于3%。

In order to determine the shear strength parallel to grain for small-diameter logs or thin lumber, this paper describes a new test method in which the width of the specimen was cut to half its standard size. The feasibility of using the modified shear specimen, as a substitute for a standard specimen, was determined by comparing the shear strength between modified and standard (specimens) from both Chinese Fir (Cunninghamia lanceolata) and Poplar I-214 [Populus × euramericana (Dode) Guineir cv.'I-214'] lumber. Results showed that the absolute values of the relative differences of the shear strength between the standard and modified specimens for matched (condition) were under 3%, and there was no significant difference at the 0.05 probability level. This provided a useful method for measuring the shear strength parallel to the wood grain for small or undersize timber.