落叶松层板分级质量评价

The Quality Appraise of Larch Lamina Grading

对落叶松胶合木用层板进行目测分级并测定其弹性模量和静曲强度,研究各等级层板的弹性模量和静曲强度及其相互之间的关系,探讨层板目测分级和机械弹性模量分级的科学性、合理性。结果表明:根据层板缺陷进行目测分级,等级高的层板其弹性模量和静曲强度的平均值和5%分位值高,目测分级能够基本反映其材质性能,具有一定的科学性与合理性;但目测分级层板弹性模量和静曲强度值的离散度很大,目测分级所能达到的准确与可靠程度决定其不能替代机械弹性模量分级。机械弹性模量分级层板的静曲强度与弹性模量呈正相关性,但各等级层板的静曲强度与弹性模量的相关系数大不相同,其静曲强度值的离散度也比较大,说明该分级方法还有改善的余地。更加科学、可靠的胶合木层板分级方法还有待进一步的探索研究。

The larch lamina made for structural laminated timber was visually graded, its MOE and MOR were measured, the relationship between each other was studied, and then the scientifieity and rationality of visual grading and mechanical grading for elasticity were explored. Results show that the visual grading according to laminas defect, high level laminas has high average and 5% quantile of MOE and MOR, and visual grading can basically reflect its material properties, with certain seientifieity and rationality. But dispersion of visual graded MOE and MOR values is quite large, visual graded is not accurate and reliable, and cannot replace machine graded. MOE and MOR are positively correlated, but correlation coefficient of each grade laminas MOE and MOR is different; dispersion of machine graded laminas and MOR is also relatively large, indicating that there is still room for improvement in classification method. And the more scientific and reliable graded methods for glulam layer board remain to be further researched.