林业工程学报2018，Vol.3Issue(4)：51-55,5.DOI:10.13360/j.issn.2096-1359.2018.04.009
单板条层积材(PSL)力学性能的各向异性
Study on the anisotropy of mechanical properties of parallel strand lumber
摘要
Abstract
This study explored the differences in the mechanical properties of parallel strand lumber with different load-ing directions. Parallel strand lumber (PSL) were made of poplar strands with 5 mm and 20 mm width. The test was carried out to measure the flexural, impact and nail-holding forces in load perpendicular to wide face of strand and load parallel to wide face of strand, and an analysis of variance was performed on the results in both directions. The results showed that the PSL mechanical properties were anisotropic. The flexural strength and flexural modulus in par-allel loading were higher than those in perpendicular loading. When vertical loading was applied, the interface layer between the adhesive layer and the single strand was prone to be damaged at the adhesive layer and early wood thin cell walls. When parallel load was applied, the strands were cracked along the glue line. The impact toughness for ver-tical loading was greater than that of parallel loading. When vertical loading was used, wood was cracked along the wood ray stretching, resulting in a rough fracture surface. When parallel load was used, the shear layer was either a layer of glue or strand, and the layer of glue was more fragile than plywood. The nail-holding forces in the vertical di-rection was greater than that in the parallel direction. When the screw was fastened in the vertical loading direction, the combined shearing and extruding actions of the thread on the single-strand fiber of poplar made the pull-out force of the screw large. When the screw was fastened parallel with the loading direction, a part of the contact area between the screw and the test piece might be a glue area, and the extrusion function and the pull-out resistance were small. Only the nailing force of the PSL, made of 5 mm wide strands, showed significant differences of P value at 0.05 level in both directions. All the mechanical properties of the PSL, made of 20 mm wide strands, showed significant differ-ences in both directions. The increase of the width of the strands made more significant anisotropy of the main strength index of the PSL.关键词
单板条层积材/杨木/力学性能/各向异性Key words
parallel strand lumber/poplar/mechanical properties/anisotropy分类
农业科技引用本文复制引用
王慧,张娅梅,朱越骅,潘彪,於朝广..单板条层积材(PSL)力学性能的各向异性[J].林业工程学报,2018,3(4):51-55,5.基金项目
中央财政林业科技推广示范项目(2015TJS07) （2015TJS07）
江苏省林业局2016软科学研究计划项目. （）
