Analyses of the lateral resistances of bolt joints and drift pin joints in timber III. Numerical analyses applying the finite element method

The nonlinear load-slip characteristics of wood joints having fasteners such as bolts and drift pins were developed using finite element analysis. The stiffness equation was obtained by employing the Anfang-parameter method assuming a beam on an elastic foundation, and the solutions were acquired by the load increment method. Elasto-plastic bending of fasteners was approximated assuming constant strain hardening above the yield,point, and bearing constants were given by the experimental equation relating bearing stress and embedment. The effect of frictional resistance between wood member and steel plate was considered in the analysis and the effect of embedment of the steel plate on lateral resistance was also considered. To verify the validity of the proposed expression, the calculated load-slip curves were compared with previous calculated and experimental results based, on tests of three types of mechanical wood joints. The comparison between calculated and experimental results showed the practical applicability of the analysis presented in this study to the calculation of lateral resistance, although some aspects remain to be investigated. In addition, for bolt joints with steel side plates, the effect of the axial force became more remarkable as the form ratio: t/d (t: thick ness of wood member, d: fastener diameter) and slip were increased.