The Fatigue Performance of Angle Cross-Frame Members in Bridges

This study investigated the fatigue performance of cross-frame connections for angles welded to connection plates. The stress concentration factors were deduced by analyzing tests and comparing the results to finite element models. Thirty tests of six different types of cross-frame members were tested using two different stress ranges in order to compare different geometric effects on stress concentration. The results of our tests indicate that using balanced welds extends the fatigue life of these members. A parametric study was then performed using ABAQUS to determine the effects of various parameters upon the stress concentration and fatigue life. The parametric study indicated that the outstanding leg length, plate thickness, plate length and angle length have a significant effect upon the stress concentration. A parametric equation was then derived using statistics to calculate the stress concentration factor using known geometric parameters.