# Bending Performance of a Prestressed Concrete Composite Girder Bridge with Steel Truss Webs
## 7 Conclusions  
(1) The experiment reveals that the PC composite girder bridge with steel truss webs undergoes distinct stages of failure, including elastic, cracking elastic, elastoplastic, and failure stages. Practical implications suggest optimizing the height-to-span ratio to enhance performance and reduce stress concentrations. During the loading process, neither the failure of joint connections nor the local buckling of the steel truss webs occurred. The structure ultimately failed due to excessive deformation, but its overall mechanical performance was good. In the elastic stage, the strain of the top and bottom plates of the PC composite girders with steel truss webs conformed to the 'plane-section assumption'.  
(2) The comparative analysis of the experimental results and FE results demonstrates that in both the elastic and elastoplastic stages, the FE results for deflection, the strain of the top and bottom plates, and the strain of truss webs closely match the experimental results. This consistency verifies the high accuracy of the nonlinear FE modeling method for composite girders with steel truss webs presented in this paper.  
(3) When the height-to-span ratio ranges between 1/16.25 and 1/9, the deformation and stress at the mid-span section of the composite girder with steel truss webs decrease as the height-to-span ratio increases. However, when the height-to-span ratio exceeds 1/11.5, the rate of the decrease in deformation and stress slows down. For the composite girder bridge with low dead weight, the deformation and stress are significantly affected by the excentric load, with the deformation and stress increase coefficients rising as the height-to-span ratio increases.  
(4) The calculation methods of the bending moment at which the bottom plate cracks, the bending moment when the reinforcements on the bottom plate yield, and the ultimate bending moment of the PC composite girder are proposed and analyzed through comparison with the experimental and FE methods. The results demonstrate that the proposed method for calculating the bending moments of a PC composite girder with steel truss webs has a high accuracy.  
This paper mainly studies the flexural performance of an external prestressing composite girder bridge with steel truss webs; a comparative study on composite girders with corrugated steel webs can be carried out in the future to clarify the flexural properties, the similarities and differences of the two different types of composite girder bridges, and their respective practical engineering application conditions.  
[PERSON] and [PERSON] conceived the analyses; [PERSON], [PERSON] and [PERSON] performed the experiment and finite element analysis and analyzed the data; [PERSON] contributed materials/analysis tools; and [PERSON] wrote the paper. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Natural Science Foundation of Fujian Province (No. 2021J011059) and the Research Start-up Fund of Fujian University of Technology (No. GY-Z20015).  
Not applicable.  
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.  
The authors declare no conflicts of interest.