Analysis on Microstructure and Mechanical Properties of Pine Laminated Veneer Lumber

摘要

In this paper, four different nondestructive testing (NDT) methods and the static bending test were conducted on the pine (Pinus sylvestris L. Var. mongolica Litven.) laminated veneer lumber (LVL). The NDT methods included the longitudinal transmission method, longitudinal vibration method, in-plane and out-plane flexural vibration method. The effects of the compression ratio on the Young's modulus and bending strength (MOR) of LVL were investigated. There were four compression ratios for different ply numbers of LVL, 8.1％ for eight-ply samples, 18.3％ for nine-ply samples, 26.5％ for ten-ply samples, 33.1％ for eleven-ply samples, respectively. The microscopic structure of the LVL was analyzed with a scanning electron microscope (SEM). The results showed that the microstructure of LVL changed greatly between different compression ratios. And the dynamic Young's modulus and static bending (MOE) and bending strength (MOR) were greatly increased when the compression ratio increased form 18.3％ to 26.5％.