Fatigue tests of stiffener to cross beam connections

Traffic loads produce high stress concentrations leading to fatigue cracking at the edges of cutouts in webs of cross beams. High local stresses can be reduced by improved shaping of cutouts. Fatigue tests were performed using two types of specimens; one with a commonly used shape of cut-out and the other with a new shape. The results showed a considerable increase of fatigue life for the new shape. However residual stresses of unknown distribution and high intensities were observed in all specimens and these may have influenced the increase in fatigue strength.