Analysis on Microstructure and Mechanical Properties of Birch Laminated Veneer Lumber

Abstract

In this paper, four different nondestructive testing (NDT) methods and the static bending test were conducted on the birch (Betula platyphylla Suk.) 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 static bending (MOE) and bending strength (MOR) of LVL with vertical load 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 MOE and MOR of LVL were increased with increasing compression ratio, and there was a strong correlation between each dynamic Young’s modulus and the static MOE.