ABSTRACT
To study the fatigue crack propagation mechanism at Haibach hole for orthotropic steel deck, the multi-scale whole-bridge digital twin model was established based on a highway-railway dual-purpose bridge case study. The digital fatigue test of the Haibach hole was carried out based on fracture mechanic theory and the eXtended Finite Element Method (XFEM). The welding process numerical simulation near Haibach hole was performed. The result shows there is the high residual tensile stress at the cutout edge. The cracks at diaphragm cutout edge and weld toe at U-rib propagation were simulated coupled with the effect of multi-stress field. The result shows that the crack could not be in the plane but will deflect a certain angle during the propagation process. The cumulative strain energy release rate result reveals that the fatigue cracks at Haibach hole edge are I mode crack and I mode crack at U-rib weld toe.
