621.177; 621.314

welded truss, experimental testing, computer simulation experiment, deformation behavior of the structure, load-bearing capacity, truss stability loss.

The deflection of a welded sub-rafter truss under external static loads applied to the nodes of the upper chord was investigated. Experimental force testing and computer simulation experiments were conducted on a physical model of the truss with dimensions of 2000x400 mm. Based on the study results, numerical and graphical data sets were obtained regarding the deflection of the investigated truss under external loads ranging from 2.5 kN to 45 kN. The results from the computer simulation closely matched those from the experimental force testing, with a 94.2% correlation, indicating linear deformation behavior. Furthermore, computer modeling was used to study the truss's deformation behavior under higher loads, identifying the locations of maximum stress concentration. The study also determined the load limits that induce the structure's ultimate state. The methodology and findings are recommended for designing such trusses to ensure high accuracy in results, thus providing the necessary durability of welded sub-rafter trusses throughout their service life.

1. Kovalchuk Y., Shynhera N. (2017) The influence of height of angular profile of rods on rectangular welded truss deformation. Scientific Journal of TNTU, vol. 88, no. 4, pp. 82–87.
2. Kovalchuk Y., Kovalchuk Y., Shynhera N. (2022) Welded truss deformation under thermal influence. Scientific Journal of TNTU, vol. 105, no. 1, pp. 13–18.
3. Zhang Zhaobo, et al. “Deflection Estimation of Truss Structures Using Inverse Finite Element Method.” Sensors 23.3 (2023): 1716.
4. Tiainen T., Mela K., Jokinen T., Heinisuo M. The effect of steel grade on weight and cost of warren-type welded tubular trusses. Proc. Inst. Civ. Eng. Struct. Build. 2017, 170, 855–873.
5. Lan X., Huang Y., Chan T.-M., Young B. (2018) Static strength of stainless steel K- and N-joints at elevated temperatures. Thin-Walled Struct, 122, pp. 501–509.
6. Efendi A. W. (2024) Behavior of welded joints on the roof truss of KOJK Office using LISA V.8 FEA – Journal of Metallurgical Engineering and Processing Technology, vol. 5, no. 1, August, , P-ISSN: 2723-6854, E-ISSN: 2798-1037, page 24-41
7. Majko J., Saga M., Sagova Z., Handrik M., Kopas P., Jakubovicova L. (2022) Numerical analysis and optimization of large dimensioned structures considering stress concentrations in welded joint. MATEC Web of Conferences, 357, 02002
8. Shao Y., He S., Zhang H., Wang Q. (2017) Behavior of tubular T-joints after exposure to elevated temperature. Ocean Eng., 129, 57–67.
9. Azari Dodaran N., Ahmadi H., Lotfollahi-Yaghin M. A. (2018) Static strength of axially loaded tubular KT-joints at elevated temperatures: Study of geometrical effects and parametric formulation. Mar. Struct., 61, 282–308.
10. Larsen Mikkel Lоvenskjold, et al. “Fatigue life estimation of the weld joint in K-node of the offshore jacket structure using stochastic finite element analysis”. Marine Structures 78 (2021): 103020.
11. Suo Y., Yang W., Chen P. (2018) Study on Hysteresis Model of Welding Material in Unstiffened Welded Joints of Steel Tubular Truss Structure. Appl. Sci., 8, 1701.
12. Larsen Mikkel Lоvenskjold, et al. “Fatigue life estimation of the weld joint in K-node of the offshore jacket structure using stochastic finite element analysis”. Marine Structures, 78 (2021): 103020.
13. Kaminski Marcin and Rafal Blonski. “Analytical and numerical reliability analysis of certain Pratt steel truss”. Applied Sciences, 12.6 (2022): 2901.
14. Khademi F. Enhancing Load Rating of Railway Truss Bridges through a Hybrid Structural Analysis and Instrumentation Procedure. Ph.D. Thesis, Illinois Institute of Technology, Chicago, ON, USA, 2017.
15. Tong G., Zhongxiang L., Jie L., Dazhang H. (2016) Diagnosis and Mitigation of Fatigue Damage in Longitudinal Diaphragms of Cable-Stayed Bridges. Journal of Bridge Engineering.
16. Hobbacher A. F., (2016) Recommendations for Fatigue Design of Welded Joints and Components  IIW Collection, Springer International Publishing.
17. Li T., Lie S.T., Shao Y. B. (2017) Fatigue and fracture strength of circular hollow section TT-joint.
    J. Constr. Steel Res, 129, pp. 101–110.

1. Kovalchuk Y., Shynhera N. (2017) The influence of height of angular profile of rods on rectangular welded truss deformation. Scientific Journal of TNTU, vol. 88, no. 4, pp. 82–87.
2. Kovalchuk Y., Kovalchuk Y., Shynhera N. (2022) Welded truss deformation under thermal influence. Scientific Journal of TNTU, vol. 105, no. 1, pp. 13–18.
3. Zhang Zhaobo, et al. “Deflection Estimation of Truss Structures Using Inverse Finite Element Method.” Sensors 23.3 (2023): 1716.
4. Tiainen T., Mela K., Jokinen T., Heinisuo M. The effect of steel grade on weight and cost of warren-type welded tubular trusses. Proc. Inst. Civ. Eng. Struct. Build. 2017, 170, 855–873.
5. Lan X., Huang Y., Chan T.-M., Young B. (2018) Static strength of stainless steel K- and N-joints at elevated temperatures. Thin-Walled Struct, 122, pp. 501–509.
6. Efendi A. W. (2024) Behavior of welded joints on the roof truss of KOJK Office using LISA V.8 FEA – Journal of Metallurgical Engineering and Processing Technology, vol. 5, no. 1, August, , P-ISSN: 2723-6854, E-ISSN: 2798-1037, page 24-41
7. Majko J., Saga M., Sagova Z., Handrik M., Kopas P., Jakubovicova L. (2022) Numerical analysis and optimization of large dimensioned structures considering stress concentrations in welded joint. MATEC Web of Conferences, 357, 02002
8. Shao Y., He S., Zhang H., Wang Q. (2017) Behavior of tubular T-joints after exposure to elevated temperature. Ocean Eng., 129, 57–67.
9. Azari Dodaran N., Ahmadi H., Lotfollahi-Yaghin M. A. (2018) Static strength of axially loaded tubular KT-joints at elevated temperatures: Study of geometrical effects and parametric formulation. Mar. Struct., 61, 282–308.
10. Larsen Mikkel Lоvenskjold, et al. “Fatigue life estimation of the weld joint in K-node of the offshore jacket structure using stochastic finite element analysis”. Marine Structures 78 (2021): 103020.
11. Suo Y., Yang W., Chen P. (2018) Study on Hysteresis Model of Welding Material in Unstiffened Welded Joints of Steel Tubular Truss Structure. Appl. Sci., 8, 1701.
12. Larsen Mikkel Lоvenskjold, et al. “Fatigue life estimation of the weld joint in K-node of the offshore jacket structure using stochastic finite element analysis”. Marine Structures, 78 (2021): 103020.
13. Kaminski Marcin and Rafal Blonski. “Analytical and numerical reliability analysis of certain Pratt steel truss”. Applied Sciences, 12.6 (2022): 2901.
14. Khademi F. Enhancing Load Rating of Railway Truss Bridges through a Hybrid Structural Analysis and Instrumentation Procedure. Ph.D. Thesis, Illinois Institute of Technology, Chicago, ON, USA, 2017.
15. Tong G., Zhongxiang L., Jie L., Dazhang H. (2016) Diagnosis and Mitigation of Fatigue Damage in Longitudinal Diaphragms of Cable-Stayed Bridges. Journal of Bridge Engineering.
16. Hobbacher A. F., (2016) Recommendations for Fatigue Design of Welded Joints and Components  IIW Collection, Springer International Publishing.
17. Li T., Lie S.T., Shao Y. B. (2017) Fatigue and fracture strength of circular hollow section TT-joint.
    J. Constr. Steel Res, 129, pp. 101–110.