R. Yan, MSc

Profile

Rui did his bachelor in Civil Engineering in Tongji University.
His master research has been done in Harbin Institute of Technology and is about post-fire behaviours of axially loaded reinforced concrete stub columns confined by square steel tubes.  

 

Research

Rui is currently working on a project about the tensile behaviour of welded X-joints with rectangular/square hollow sections made of high strength steel (HSS). The design rule for this type of connection is available in EC3-1-8 but only valid for mild steel. Considering the low ductility of HSS, an additional material reduction factor is applied in order to implement the design rule on X-joints made of HSS. However, the material reduction factor is not validated by any experimental or numerical study yet. It is a question of whether the material reduction factor is too conservative or not. Therefore, 18 X-joints made of S355, S500, and S700 are tested experimentally.

Funding organization: SSAB

Rui is currently working on a project about the tensile behaviour of welded X-joints with rectangular/square hollow sections made of high strength steel (HSS). The design rule for this type of connection is available in EC3-1-8, but only valid for the mild steel. Considering the low ductility of HSS, an additional material reduction factor is applied in order to implement the design rule on X-joints made of HSS. However, the material reduction factor is not validated by any experimental or numerical study yet. It is a question of whether the material reduction factor is too conservative or not. Therefore, 18 X-joints made of S355, S500, and S700 are tested experimentally.

In addition, coupon specimens with a transverse butt weld in the middle are tested in tension to establish the stress-strain relationship for the heat affected zone (HAZ) and the weld. The digital image correlation (DIC) system is used to measure the local deformation of the specimen. Furthermore, the GTN damage model is calibrated for HAZ and the base material. The calibrated damage model and the constitutive property are used in the numerical study of the welded X-joints. Finally, the validity of the material reduction factor could be verified.

From 2018 to 2020, Rui worked on the innovative 3D joint (INNO3DJOINT) project, funded by Research Fund for Coal and Steel (RFCS). Two types of asymmetric bolted column splices for square hollow sections were investigated experimentally and numerically. The advantage of the asymmetric column splices is that there is no space requirement between the façade panels and the column whilst the easy assembly feature remains.

A primary challenge for this study is how to determine the effective length of the yield line on the end plate, since the design rules in EC3-1-8 is only valid for the bolted end plate connection with open cross sections while square hollow sections are used in this research. Based on the experimental and numerical study, design recommendations, under the framework of the component method, are proposed.

  • CIE4115 – Steel Structures 2
  • CIE4121 – Steel Structures 3

Yan R, Xin H, Veljkovic M. Identification of GTN damage parameters as a surrogate model for S355[C]//Proc. 17th Int. Symp. Tubul. Struct., Singapore. 2019.

Liu F, Yang H, Yan R, et al. Experimental and numerical study on behaviour of square steel tube confined reinforced concrete stub columns after fire exposure[J]. Thin-Walled Structures, 2019, 139: 105-125.

Rui Yan

PhD Candidate

  • + 31 15 27 85716
  • R.Yan@tudelft.nl
  • Faculty of Civil Engineering and Geosciences

    Building 23

    Stevinweg 1 / PO box 5048

    2628 CN Delft / 2600 GA Delft

     

    Room S2 2.59

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Department:
Engineering Structures

Section:
Steel and Composite Structures

Availability:
Mon - Fri

Secretary:
Claire de Bruin