Models research for fatigue loading in highway steel bridges

At present, no fatigue load spectrum or fatigue truck is defined in highway bridge specifications in China. For the sake of selecting proper fatigue truck in fatigue design or fatigue estimation for highway steel bridges, finite-element models of simple supported steel bridges and continuous steel bridges were made. The comparative researches were carried out on fatigue damages caused between fatigue truck models in American AASHTO specification and British BS5400 specification to the live vehicle loads used in strength design in China. According to the finite-element computation results, the fatigue damages caused by some strength trucks after weight revised were close to AASHTO fatigue truck and BS5400 fatigue truck in mid-span of simple supported bridges and support section of continuous bridges. The results showed some strength vehicle loads can be used in fatigue researches for highway steel bridges after weight revised with no change on the weight ratio of different axles.