Nonlinear finite element modeling of timber scarf joints with and without steel pins

This study numerically evaluates the behavior of timber scarf joints with and without steel pins using finite element models across various parameters. Three-dimensional (3D) nonlinear finite element models were developed based on a micro modeling approach to examine their response to static loads. Experimental results were used to calibrate and validate the numerical models. Experimental results were used to calibrate and validate the numerical models. Sensitivity analysis revealed that the material properties of the scarf members were the most critical factor in achieving strong connections, surpassing the influence of key or dowel members. Simulation accuracy improved with smaller mesh sizes, increased load increments, and more iterations, though at the expense of higher complexity and longer computation times. Parametric analysis provided deeper insights into scarf joint behavior under tension and compression loads parallel to the grain. Analysis on the geometric parameter revealed that the basic size proportions recommended in the literature provide the best combination, offering greater strength compared to other size combinations. Additionally, timber scarf joints were analyzed with varying numbers of steel or wooden dowels, focusing on identifying the impact of the dowel to scarf joints. This study highlights the potential of using numerical modeling to evaluate scarf joints, while acknowledging the limitations of the tools.