Tension perpendicular to grain strength of wood, Laminated Veneer Lumber (LVL) and Cross-Banded LVL (LVL-C)

Recent experimental tests carried out on structural timber members have highlighted the importance of tension perpendicular to grain strength, particularly in beams with holes and notches, in connection regions, in curved beams, and in post-tensioned timber frames. Innovative engineered wood products such as Cross Banded Laminated Veneer Lumber (LVL-C) have been introduced into the market specifically to improve the perpendicular to grain properties of normal Laminated Veneer Lumber (LVL). This paper reports on tests that were performed at the University of Canterbury using specimens of sawn timber Radiata Pine, LVL and LVL-C. The perpendicular to grain tension strengths of LVL was generally lower than those for sawn timber, but the LVL-C showed a significantly improved strength. The paper also compares the experimental results with strengths predicted using both coupled elastic Finite Element Method (FEM) and Linear Elastic Fracture Mechanics (LEFM) models. These models were found to predict the average strength with reasonable accuracy. © 2011 Taylor & Francis Group, London.