Analysis on Influence of Externally Prestressed Tendons on Fundamental Frequency of Continuous Box Girder with Corrugated Steel Webs

Research purposes: In order to research the influence of externally prestressed tendons on the dynamic property of a continuous box girder with corrugated steel webs (CBGCSW), according to structure vibration theory and mechanical properties of composite girder, the formula of natural vibration frequency of CBGCSW under external prestressing is derived. Based on a double span continuous test girder with corrugated steel webs, a numerical analysis model is established by finite analysis software ANSYS for modal analysis. The theoretical calculation value, test value and finite element calculated value are analyzed to demonstrate the applicability of theoretical formula. The theoretical calculation and the numerical simulation are combined to research the influence of magnitude of the prestressing force, cross sectional area and the anchor position on natural vibration frequency of CBGCSW. Research conclusions:(1) Results analysis between theoretical calculation value, test value and finite element calculated value show that the formula is applicable. (2)The magnitude of the prestressing force has little effect on the natural vibration frequency of CBGCSW. (3)The natural vibration frequency of continuous box girder with corrugated steel webs is obviously affected by the variation of the sectional area of externally prestressed tendons. (4)The natural vibration frequency of continuous box girder with corrugated steel webs decreases with the decrease of externally prestressed tendons anchorage position. (5)The research results can provide some reference for the dynamic characteristics research and structural design of the external prestressed CBGCSW, and provide a theoretical basis for the impact coefficient estimation of the composite structure. © 2021, Editorial Department of Journal of Railway Engineering Society. All right reserved.