effect of cross-frame spacing on the modal properties of curved bridges

parametric studies have been conducted to investigate the effect of variation in the number of crossframes on the free vibration response of curved steel bridges such as natural frequencies and mode shapes. the numerical simulations were performed using the general-purpose finite element software package abaqus and validity of the results verified comparing them with experimental results of other researchers. according to the results, when cross-frame spacingisselected in a certain range, the number of cross-frames, especially in low modes, has negligible effect on the free vibration frequencies of a curved bridge. nevertheless, in the higher modes, this effect is considerable.