Fracture simulation of welded RHS X-joints using GTN damage model

A welded rectangular hollow section (RHS) X-joint exposed to tension loading has three typical fracture-related failure modes: Punching shear (PSF), Brace (BF), and Chord side wall (CSWF). Prediction of these modes by finite element (FE) simulations requires modelling the material damage. An appropriate damage model accurately predicts behaviour fracture zone provides necessary information improve design rules for high-strength steel (HSS) RHS X-joints based on parametric studies using validated model. In this paper, parameters Gurson-Tvergaard-Needleman (GTN) are calibrated base (BM) heat-affected (HAZ) butt-welded cold-formed connections, no appeared in weld. computational homogenisation analysis is carried out representative volume (RVE) models calibrate pressure-dependent yield surface GTN model, considering different combinations accumulated initial hardening strain void fraction (VVF) due a varying stress triaxiality. The critical final VVFs against tensile coupon tests. Finally, BM HAZ used simulation nine monotonic tension. FE successfully experimental load-displacement relationships fractured zone, indicating could effectively be study X-joints. possible improvements outlined future studies.