As a common type of joint used in spatial grid structures, the tensile performance of bolt-sphere joints directly affects the safety of the spatial grid structure under fire. To study the tensile properties of the bolts in sphere joints under fire, the four sets of 36 bolt-sphere joints consist of M20, M24, M30, and M36 high-strength bolts were conducted in elevated temperature by steady-state test. Therefore, the tensile bearing capacity of the bolt-sphere joint was obtained under different elevated temperatures. Experimental results show the destroyed section of the bolt-sphere joint that occurs in the thread of the high-strength bolt at the intersection of the sphere because of the maximum concentration of stresses that occurred in areas of destruction. The brittle fracture of bolt-sphere joints happened when the temperature is below 400 ℃. As the temperature increased, the neck shrinkage of the damaged section of the bolt becomes more apparent, and the ductile failure of the bolt-sphere joint occurred. The stiffness and the bearing capacity of bolt-sphere joints decreased gradually as the temperature rose. Conversely, the ductility was gradually increasing. When the temperature was greater than 300 ℃, the stiffness and the bearing capacity of the bolts in sphere joint decreased rapidly. The bearing capacity reduction coefficient of the high-strength bolts with different diameters were next to the same at elevated temperatures. According to the experimental data, the formulas of the tensile bearing capacity reduction coefficient of bolt-sphere joints were obtained.
This is a preview of subscription content, log in to check access.
Buy single article
Instant access to the full article PDF.
Price includes VAT for USA
Fan, X. M. (2013). The displacement and internal force analysis of steel grid structure after fire. Master’s thesis, Beijing: Beijing University of Technology (in Chinese).
Jiao, J. F., Lei, H. G., & Chen, Y. F. (2018). Experimental study on variable-amplitude fatigue of welded cross plate-hollow sphere joints in grid structures. Advances in Materials Science and Engineering,2018, 1–15.
Kirby, B. R. (1995). The behaviour of high-strength grade 8.8 bolts in fire. Journal of Constructional Steel Research,33, 3–38.
Lange, J., & Gonzalez, F. (2012) Behavior of high-strength grade 10.9 bolts under fire conditions. Structural Engineering International, 22(4), 470–475.
Li, F., Zhu, R. J., & Zhang, D. D. (2018). Mechanical behaviour of high strength aluminum alloy bolt-ball joint system under axial load and initial stiffness computational model. Journal of Building Structures,39(S2), 103–111. (in Chinese).
Li, G. Q., Jiang, S. C., Yin, Y. Z., Chen, K., & Li, M. F. (2003). Experimental studies on the properties of constructional steel at elevated temperatures. Journal of Structural Engineering,129(12), 1717–1721.
Liu, X. L., & Chen, Z. H. (1994). Analysis of collapse mechanism of welded hollow sphere joint in space trusses and experimental research of its bearing capacity. Journal of Building Structures,15(3), 38–44. (in Chinese).
Lopez, A., Puente, I., & Aizpurua, H. (2011). Experimental and analytical studies on the rotational stiffness of joints for single-layer structures. Engineering Structures,33, 731–737.
Ma, H. H., Fan, F., Ke, J., & Cao, Z. G. (2010). Experimental research on semi-rigid joints used in grid structures and reticulated domes. Journal of Building Structures,31(11), 65–71. (in Chinese).
Niu, F. M. (2011). The accident analysis and reflection of American New York Word Trade Center Building. Architectural and Structural Design,9, 69–72. (in Chinese).
Pang, X. P., Hu, Y., Tang, S. L., Xiang, Z., et al. (2019). Physical properties of high-strength bolt materials at elevated temperatures. Results in Physics,13, 1–11.
Qu, C. Y., Liu, D. D., & Chen, G. G. (2018). Research on fire resistance ability of the large-space steel truss. Building Structure,48(S2), 534–537. (in Chinese).
Rahnavard, R., Siahpolo, N., Naghavi, M., & Hassanipour, A. (2014). Analytical study of common rigid steel connections under the effect of heat. Advances in Civil Engineering,2014, 1–10.
Rahnavard, R., & Thomas, R. J. (2018). Numerical evaluation of the effects of fire on steel connections; part 1: Simulation techniques. Case Studies in Thermal Engineering,12, 445–453.
Rahnavard, R., & Thomas, R. J. (2019). Numerical evaluation of the effects of fire on steel connections; part 2: Model results. Case Studies in Thermal Engineering,13, 1–9.
Shen, C. W., Chen, S. L., & Gan, S. P. (2002). Repairing construction of lattice grid structure for CCTV Taihu photostudio after fire. Steel Construction,1(17), 44–46. (in Chinese).
Tian, L. M., Wei, J. P., Hao, J. P., & Wang, X. T. (2017). Dynamic analysis method for the progressive collapse of long-span spatial grid structures. Steel and Composite Structures,23(4), 435–444.
Wei, J. P., Tian, L. M., & Hao, J. P. (2018). Improving the progressive collapse resistance of long-span single-layer spatial grid structures. Construction and Building Materials,171, 96–108.
Zhai, C. M. (2014). Research on damage evaluation of steel structures in the high-rise building based on TVCC fire disaster. Master’s thesis. Tianjin: Tianjin University (in Chinese).
The authors would like to acknowledge that this research was supported by the Nanjing Gongda Construction Technology Co. Ltd.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Huang, B., Lu, M., Fu, Y. et al. Experimental Investigation on Tensile Properties of the Bolt in Sphere Joints Under Fire. Int J Steel Struct (2020). https://doi.org/10.1007/s13296-020-00368-8
- Bolt-sphere joints
- High temperature
- Tensile properties
- Experimental study
- Predictive equation