# Stress Behaviors at Rib-to-Floorbeam Weld and Cutout Details under Controlled Truck Loading
## 5 Conclusions  
To investigate the stress behaviors of the RF and Cutout details on the OSD, controlled truck tests and FEA were carried out. The following conclusions and remarks were reached.  
Figure 20: Stress contours and deformation plots under LC2. (**a**) \(Z\) = 0 m; (**b**) \(Z\) = 1.5 m; (**c**) \(Z\) = 3.0 m; (**d**) \(Z\) = 3.6 m; (**e**) \(Z\) = 6 m; (**f**) \(Z\) = 7.4 m. (Unit: MPa).  
1. Stresses at the RF and Cutout details present significant local effects to wheel loads in the bridge transverse direction. When the details are underneath the deck plate that is covered by the tire width, apparent stresses are produced at these details; otherwise, their stresses are small. Therefore, considering a passing truck, the stress at the RF and Cutout details generated by one side of wheel do not superimpose with that from the other side of wheel. Furthermore, the loading effects at the details, produced by multiple trucks traveling side-by-side, can be ignored.
2. In the bridge longitudinal direction, apparent stresses can generate at the RF and Cutout details only when the wheels load on the deck between the adjacent floor beams; otherwise, wheel loading effects are negligible.
3. The FEA results shows that the stresses at the RF-R, RF-F and Cutout details are compressive, while the stress at the RF-W detail is in tension. The stress at the RF-W detail is significantly larger than that at the RF-R and RF-F details due to rib wall outward bending, and more attention should be paid to the RF-W detail based on fatigue consideration.
4. Comparisons between the FEA and field measurements confirm that the riding-rib-wall loading is the most critically transverse loading location, and under the passage of the tandem axles, only one stress cycle is produced at the four details.
5. Due to the offset of wheel loads, the floor beams may suffer from severe out-of-plane bending, while the ribs may experience warping and distortion. This is why high stresses appear at the RF-W detail.  
This paper mainly focused on the stress behaviors of the RF and Cutout details under wheel loads, and further research is needed to develop an approach that could improve the fatigue performance of the details, which is the next stage of the study.  
Conceptualization, J.L. and Z.Z.; methodology, Z.Z.; software, J.L.; validation, Z.Z.; formal analysis, J.L.; investigation, J.L.; resources, Z.Z.; data curation, J.L. and Z.Z.; writing--original draft preparation, J.L. and Z.Z.; writing--review and editing, J.L.; project administration, Z.Z.; funding acquisition, Z.Z. All authors have read and agreed to the published version of the manuscript.  
This research was supported by the National Natural Science Foundation of China (grant number 51878269); the STU Scientific Research Foundation for Talents of China (grant number NTF18014); and the Teaching Team Development Program of Guangdong Higher Education Institutes of China.  
Not applicable.  
Data Availability Statement: Data is contained within the article.  
The authors declare no conflict of interest.  
The following abbreviations are used in this manuscript:  
OSDs  orthotropic steel decks RF rib-to-floorbeam RF rib side of rib-to-floorbeam connection RF-F floorbeam side of rib-to-floorbeam connection RF-W wrap-around weld of rib-to-floorbeam connection FEA finite element analysis RD rib-to-deck plate UHPC ultra-high-performance concrete F3 third floorbeam R11 eleventh rib W west side E east side LC loading case