Fatigue assessment and crack propagation of floorbeam cutout in orthotropic bridge decks

Abstract

Based on the fatigue cracking of floorbeam cutout in a bridge, the field testing under random traffic flows was firstly conducted to investigate the fatigue crack initiation, and then a multi-scale numerical model, based on extended finite element method (XFEM), was established to reveal the propagation mechanism of crack growth. It was found that floorbeam cutout exhibits a complex three-dimensional deformation state under wheel loads, leading to an I-II-III mixed crack growth mode. The crack propagation direction is normal to the free edge of floorbeam cutout, which is the crack propagation direction at initiation. Increasing floorbeam thickness can facilitate preventing the crack propagation of floorbeam cutout.

Keywords

• Orthotropic bridge deck
• Fatigue
• Extended finite element method (XFEM)
• Floorbeam cutout
• Crack propagation