The box girder with corrugated steel webs is a new steel-concrete composite bridge structure. Based on the theory of stress related material damping, using the unit volume dissipation factor of corrugated steel webs and reinforced concrete, the dissipation factor formula of composite box girder with corrugated steel webs is deduced through the energy method. The dissipation factor is obtained from combining the stress of each element which is computed by the finite element method. The equivalent damping ratio is calculated according to the equal energy dissipation in one cycle, and compared to the measured results. The analysis results show that: the material damping of composite box-girder bridges with corrugated steel webs is not a fixed value; it is increased with the stress level’s increasing. Under the state of free vibration and vehicle load excitation, the damping ratio of composite box-girder with corrugated steel webs is suggested as 0.3%. The formula of dissipation factor and calculation of equivalent damping ratio suggested can provide evidence for the damping value in dynamic analysis of composite box girder bridges with corrugated steel webs.
Li Bo;Liu Bao-dong;LiPeng-fei.
The study on stress related damping characteristic of composite box-girder with corrugated steel webs[J]. Journal of Vibration and Shock, 2012, 31(6): 68-71
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