Prediction of Withdrawal Resistance of Single Screw on Korean Wood Products

In this article, withdrawal resistances of axially loaded self-tapping screws on wood products made by Korean Larch were predicted with existing estimation equation, and compared with experimental test data. The research was required because no design methodology for the withdrawal resistance of self-tapping screw is present in Korean building code (KBC). First, the withdrawal resistance of wood screw was predicted to use the withdrawal design value estimation equation in National Design Specification for Wood Construction (NDS). Second, three types of wood products, solid wood, cross-laminated timber (CLT) and plywood, were utilized for withdrawal test. For decades, various engineered wood products have been developed, especially cross-laminated timber (CLT) and hybrid timber composites such as timber composites of solid wood and plywood. Therefore, CLT and plywood were also investigated in this study as well as solid wood. Finally, the predicted values were compared with experimentally tested values. As the results, the tested values of solid wood and CLT were higher than the predicted values. In contrast, it is inaccurate to predict withdrawal resistance of plywood since prediction was higher than tested values.