## 4 Discussion and Conclusions  
The problem of stress variations in the swiveling support system of a large tonnage asymmetric T-shaped rigid swiveling bridge has been investigated in this paper. The bridge model was built using SolidWorks, and the bridge swiveling process was numerically modeled using Ansys. The main conclusions are as follows:  
(1) During rotation, the maximum compressive stress in the upper turntable is located in the contact area with the outer edge of the upper steel spherical hinge; the stress value is  
Figure 28: Data comparison chart of simulation and test: (**a**) numbered 1-1 and 1-2; (**b**) numbered 1-3 and 1-4; (**c**) numbered 1-5 and 1-6; and (**d**) numbered 1-7 and 1-8.  
33.806 MPa, and the stress gradually decreases in all directions. The maximum compressive stress of the steel spherical hinge is located at the edge of its own circumference and is accompanied by stress concentration. The maximum compressive stress values of the upper and lower steel spherical hinges are 95.546 MPa and 98.04 MPa, respectively, and the stress decreases with the decrease in the radius of the steel spherical hinge.  
(2) Under the theoretical transverse, longitudinal, and longitudinal-transverse limiting eccentricity conditions, the stress on the upper turntable has reached 39.103 MPa, 38.02 MPa, and 39.316 MPa, respectively. All of the above exceed the allowable stress value of the material, while the steel spherical hinge still meets the design requirements, so the ultimate eccentricity of the rotating bridge is mainly affected by the strength of the upper turntable. The transverse, longitudinal, and longitudinal-transverse limit bias loads of this bridge are 210 mm, 200 mm, and 180 mm, respectively.  
(3) Under the three eccentric working conditions, the stress change rule of each member is the same; only the stress value and the direction of stress concentration are different. The maximum stress value point is located in the eccentric position, and it increases with the increase in eccentricity. In descending order, the effects of the three eccentricity conditions on this bridge were transverse axial, longitudinal axial, and longitudinal and transverse axial bias loads. In order to ensure the safety of the project, it is necessary to focus on the influence of each eccentricity condition on the bridge turning process.  
(4) During the actual turning process, due to the interference of the external load, the change amplitude of the stress value at each monitoring point is within the interval of 0-5 MPa. The measured values of each monitoring point are consistent with the trend of simulation values. The monitoring method of deploying stress gauges at the steel support structure of the lower bearing platform provides a new method to obtain the stress pattern of the steel spherical hinge and even the bridge as a whole.  
Methodology, E.Z.; software, Y.W.; validation, E.Z.; formal analysis, S.G.; resources, Y.W.; data curation, Y.W.; writing--original draft preparation, Y.W.; writing--review and editing, E.Z. and H.L.; visualization, P.L.; supervision, E.Z. and H.L.; project administration, H.L. All authors have read and agreed to the published version of the manuscript.  
Not applicable.  
The original contributions presented in the study are included in the article; further inquiries can be directed to the corresponding author.  
The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.