Effects of a New Method on Stress Amplitude and Fatigue Life of Orthotropic Steel Box Girder

In this study, a new method of replaceable supporting member within orthotropic steel box girder is proposed in order to reduce stress amplitude and improve fatigue life of orthotropic steel box girder. The component model was established by ABAQUS, and the experiment was conducted to analyze stress amplitude of easily fatigue cracking areas of orthotropic steel box girder with and without the supporting member. In addition, the fatigue life was analyzed and predicted. The comparison results show that the finite element analytical results are in good agreement with the experimental results. The reduced proportion of stress amplitude of U rib, T rib grooves and mid-span of top plate of orthotropic steel box girder range from 40% to 60% and 20% to 40%, respectively. The analytical results show that the stress amplitude of orthotropic steel box girder can be reduced by the similar extent with the addition of the same supporting member under different loading pressure; The supporting member can improve the fatigue life of orthotropic steel box girder pertinently, which is simple in construction and low in cost, and can provide suggestions for solving fatigue problem of orthotropic steel box girder in engineering practice.