Table 3: A comparison of natural frequency of the bridges.

Number of steel girders Type of composite bridgesNatural frequency (Hz) Percent difference (%)
From (4) and (5)From FE model

3 Unstrengthened/strengthened
with CFRP sheets
7.8947.7941.27
Strengthened with CFRP deck10.47610.4230.51

5Unstrengthened/strengthened
with CFRP sheets
9.3989.3240.79
Strengthened with CFRP deck11.10610.9211.67