Research on bending properties of dowel laminated veneer lumber

Abstract

Dowel laminated veneer lumber (DLVL) is a new form of laminated veneer lumber (LVL), consisting of several LVL laminas connected by wood dowels in a horizontal direction. DLVL can serve as a large cross-section panel, exhibiting high prefabrication. The bending properties of DLVL panels were examined through experimental and simulation methods. DLVL panels were processed using short hardwood dowels and thin LVL laminas made of small-diameter logs. The four-point bending tests were conducted to investigate the bending properties of DLVL panels. The influence of the lamina variables, such as width, thickness, quantity, and dowel spacing, on the bending strength and effective bending stiffness of DLVL panels was investigated by the extended finite element analysis method. The prediction formulas of the bending capacity and effective bending stiffness of DLVL panels were proposed and optimized using the limit strain method and multivariate analysis. The findings indicated that the failure mode of DLVL panels manifested as a tensile-shear failure of LVL laminas. The bending properties of DLVL panels were affected by the cross-sectional size and quantity of LVL laminas. The bending properties of DLVL were equivalent to that of commonly used engineered wood products. The proposed correction coefficients of the bending capacity and effective bending stiffness of DLVL panels under the influence of variables could enhance the accuracy of the prediction formulas. The optimized formulas could predict the bending capacity and effective bending stiffness of DLVL panels, whose errors were within ± 13 %.