单板接缝对LVL力学性能的影响

将LVL中的单板接缝分别配置在表芯层、同一垂直面上、错开的相邻层,并对所测得的力学性能进行分析,结果表明:除最外3层同位接缝外,其他接缝板材的3点弯曲和4点弯曲静曲强度和弹性模量都大于无接缝板A。同位接缝的水平剪切强度按接缝11,5,6,7和9层递增。表背3层接缝错开对板材的静曲强度提高幅度高于芯层5层接缝错开的影响; 弹性模量在表背3层随着接缝错开距离的增加而升高,随着芯层5层接缝错开距离的增加而减小。
Veneers of laminated veneer lumber(LVL)were joined by scarf joints. The positions of the joints were either the same in adjacent layers or not. Mechanical properties of the lumber were investigated. It was found that joined veneers improved the modulus of elasticity(MOE)and modulus of rupture(MOR)of the lumber except for samples with the same position joints in the outer 3 layers. For samples with the same position joints, the 9-layer joint arrangement exhibited the highest horizontal shear strength, followed by 7-layer, 6-layer, 5-layer and 11-layer arrangement. For samples where the joint positions were not the same, the MOR of the samples with joints in the 3 outer layers was higher than those with joints in the 5 core layers. In the 3 outer layers, the MOE increased with the increasing of the adjacent joints distance. However, in the 5 core layers, it decreased with the increasing of adjacent joints distance