Effect of the vent hole geometry and welding on the static strength of galvanized RHS K-joints by FEM and DOE

This research paper aims to evaluate the influence of different vent hole geometries and welding on the strength of galvanized rectangular hollow sections K-joints typically used in tubular warren lattice girders. On the one hand, four different hole geometries were considered in this study, taking into account the standard recommendations and manufacturers suggestions. On the other hand, residual stresses derived from welding thermal loads on the RHS K-joints between tubular profiles were taken into account. Next, a nonlinear buckling analysis for each type of hole was undertaken and the numerical results have been validated in comparison with Eurocode 3-Part1.8. Finally, a design of experiments based on the previous FEM models was developed and a hundred different nonlinear buckling analyses were calculated, showing clearly the different joint failures, both in chord and braces. Surface response from each DOE analysis is presented and the most important conclusions of this work are exposed.