Skip to main content

Post-Fire Performance of Butt-Welded Connections in ST-37 Steel


In light of the weakness of steel structures against fire and the welding process in steel structures connections, realizing the post-fire behavior of the welding after experiencing different temperature levels is vital in modeling and analyzing a structure. In this study, the behavior of butt-welded connections after experiencing different temperature levels has been investigated. The number of 168 specimens and different St-37 steel plate thicknesses (6, 8, 10, 12, 15, 20, 25, and 30 mm) are heated under seven temperature levels of 25, 100, 250, 400, 500, 700, and 900°C, and after the cooling phase, tensile tests are implemented to determine the stress–strain diagram. By examining the resulting stress–strain diagrams, the samples mechanical properties, including yield stress, ultimate stress, and elasticity modulus, are evaluated after different temperatures. The experimental results reveal that the ultimate strength, yield strength, and elasticity modulus of samples are restored to an average of about 82, 79, and 82%, respectively, after being exposed to 900°C and the subsequent cooling phase. Additionally, penetration welds have shown acceptable performance in post-fire conditions, and the failure mode of the majority of samples is the rupture of steel plates.

This is a preview of subscription content, access via your institution.

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14


  1. Kodur V, Kumar P, Rafi MM (2019) Fire hazard in buildings: review, assessment and strategies for improving fire safety. PSU Res Rev.

    Article  Google Scholar 

  2. Ketabdari H, Saedi Daryan A, Hassani N, Safi M (2021) Fire response of steel connections using gene expression programming and finite element method. Struct Des Tall Spec Build 30(11):e1862

    Article  Google Scholar 

  3. Saedi Daryan A, Yahyai M (2009) Modeling of bolted angle connections in fire. Fire Saf J 44(7):976–988

    Article  Google Scholar 

  4. Yahyai M, Daryan AS (2013) The study of welded semi-rigid connections in fire. Struct Des Tall Spec Build 22(10):783–801

    Article  Google Scholar 

  5. Maraveas C, Fasoulakis Z, Tsavdaridis KD (2017) Post-fire assessment and reinstatement of steel structures. J Struct Fire Eng.

    Article  Google Scholar 

  6. Lawson RM (1990) Behaviour of steel beam-to-column connections in fire. Struct Eng 68:263–271

    Google Scholar 

  7. Al-Jabri KS, Burgess IW, Lennon T, Plank RJ (2005) Moment–rotation–temperature curves for semi-rigid joints. J Constr Steel Res 61(3):281–303

    Article  Google Scholar 

  8. Saedi Daryan A, Yahyai M (2009) Behavior of bolted top-seat angle connections in fire. J Constr Steel Res 65(3):531–541

    Article  Google Scholar 

  9. Saedi Daryan A, Yahyai M (2009) Behaviour of welded top-seat angle connections exposed to fire. Fire Saf J 44(4):603–611

    Article  Google Scholar 

  10. Hosseini SA, Zeinoddini M, Saedi Daryan A, Rahbari M (2014) Model fire tests on a beam-to-leg connection in an offshore platform topside. Fire Mater 38(5):529–549

    Article  Google Scholar 

  11. Fischer EC, Varma AH (2017) Fire resilience of composite beams with simple connections: parametric studies and design. J Constr Steel Res 128:119–135

    Article  Google Scholar 

  12. Outinen J, Mäkeläinen P (2004) Mechanical properties of structural steel at elevated temperatures and after cooling down. Fire Mater 28(2–4):237–251

    Article  Google Scholar 

  13. Qiang X, Bijlaard FS, Kolstein H (2012) Post-fire mechanical properties of high strength structural steels S460 and S690. Eng Struct 35:1–10

    Article  Google Scholar 

  14. Qiang X, Bijlaard FS, Kolstein H (2013) Post-fire performance of very high strength steel S960. J Constr Steel Res 80:235–242

    Article  Google Scholar 

  15. Gunalan S, Mahendran M (2014) Experimental investigation of post-fire mechanical properties of cold-formed steels. Thin-Walled Struct 84:241–254

    Article  Google Scholar 

  16. Wang W, Liu T, Liu J (2015) Experimental study on post-fire mechanical properties of high strength Q460 steel. J Constr Steel Res 114:100–109

    Article  Google Scholar 

  17. Saedi Daryan A, Ketabdari H (2019) Mechanical properties of steel bolts with different diameters after exposure to high temperatures. J Mater Civ Eng 31(10):04019221

    Article  Google Scholar 

  18. Ketabdari H, Saedi Daryan A, Hassani N (2019) Predicting post-fire mechanical properties of grade 8.8 and 10.9 steel bolts. J Constr Steel Res 162:105735

    Article  Google Scholar 

  19. Hanus, F., Zilli, G., & Franssen, J. M. (2011). Experimental tests and analytical models for welds and grade 8.8 bolts under heating and subsequent cooling. Journal of Structural Fire Engineering

  20. Zhang G, Zhu MC, Kodur V, Li GQ (2017) Behavior of welded connections after exposure to elevated temperature. J Constr Steel Res 130:88–95

    Article  Google Scholar 

  21. Liu H, Liao X, Chen Z, Huang SS (2017) Post-fire residual mechanical properties of steel butt weld—experimental study. J Constr Steel Res 129:156–162

    Article  Google Scholar 

  22. El Ghor AH, Hantouche EG, Morovat MA, Engelhardt MD (2021) Rate-dependent behavior of transverse welded lap joints at elevated temperatures. J Structr Eng 147(2):04020317

    Article  Google Scholar 

  23. ASTM. ASTM E8: Standard test methods for tension testing of metallic materials. West Conshohocken: American Society for Testing and Materials; 2009.

  24. Meyers M, Chawla K (2009) Mechanical behavior of materials. Cambridge University Press, New York

    MATH  Google Scholar 

  25. Bahirai M, Gerami M, Bahaari Zargar V (2020) Postannealing mechanical properties of structural steel St37. J Mater Civ Eng 32(7):04020152

    Article  Google Scholar 

  26. Li GQ, Lyu H, Zhang C (2017) Post-fire mechanical properties of high strength Q690 structural steel. J Constr Steel Res 132:108–116

    Article  Google Scholar 

  27. Zhou X, Xue X, Shi Y, Xu J (2021) Post-fire mechanical properties of Q620 high-strength steel with different cooling methods. J Constr Steel Res 180:106608

    Article  Google Scholar 

  28. Lu J, Liu H, Chen Z, Liao X (2016) Experimental investigation into the post-fire mechanical properties of hot-rolled and cold-formed steels. J Constr Steel Res 121:291–310

    Article  Google Scholar 

  29. Xu F, Liu H, Chen Z, Li H, Feng X (2019) In-fire and postfire mechanical properties of duplex stainless steel S22053. J Mater Civ Eng 31(10):04019210

    Article  Google Scholar 

  30. Sem MTI (1999) Mechanical behavior of materials. I- Semester 3:3

    Google Scholar 

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to Amir Saedi Daryan.

Ethics declarations

Conflict of interest

Authors declare that they have no conflict of interest.

Ethical Approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Saedi Daryan, A., Barzvar, H., Fakharzadeh Naeini, E. et al. Post-Fire Performance of Butt-Welded Connections in ST-37 Steel. Fire Technol 59, 691–711 (2023).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Complete butt-welded connections
  • ST-37 steel plates
  • Mechanical properties
  • Post-fire
  • Yield strength
  • Ultimate strength
  • Elasticity modulus
  • Failure mode