Experimental Study on SNCF of Welded CHS-CFSHS T-Joints under Axial Loading

2010 ◽  
Vol 163-167 ◽  
pp. 127-131
Author(s):  
De Lei Yang ◽  
Le Wei Tong ◽  
Xiao Lin Zhao
Keyword(s):  
Experimental Study ◽  
Axial Loading ◽  
T Joints ◽  
Strain Concentration ◽  
Hollow Section ◽  
Lower Strain ◽  
Tension And Compression ◽  
Concentration Factors ◽  
Intersection Line ◽  
Circular Hollow Section

The initiation position can be predicted by studying on strain concentration factors (SNCF) and SNCF distributions. This paper concerns an experimental investigation of SNCF of welded T-joints composed of circular hollow section (CHS) braces and concrete-filled square hollow section (CFSHS) chords under axial loading on the braces with two load cases of tension and compression. Static experiments were performed on eight test specimens designed for considering different non-dimensional geometric parameters and C50 grade concrete. Compared with joints made of CHS-SHS, the experimental results indicate that the CHS-CFSHS T-joints have lower strain concentration factors which may increase fatigue strength. The position of the maximum SNCF is usually located at 00 or 900 of the intersection line between a CHS brace and a CFSHS chord.

Experimental study on axially loaded square hollow section T-joints under fire conditions

2020 ◽  
Vol 114 ◽  
pp. 102993 ◽  
Author(s):  
Jolanta Bączkiewicz ◽  
Mikko Malaska ◽  
Sami Pajunen ◽  
Mika Alanen ◽  
Markku Heinisuo
Keyword(s):  
Experimental Study ◽  
T Joints ◽  
Hollow Section ◽  
Axially Loaded ◽  
Fire Conditions

Axial strength of steel circular hollow section (CHS) X-joints strengthened by flanged larger pipe

2020 ◽  
Vol 47 (3) ◽  
pp. 301-316
Author(s):  
Peter Gerges ◽  
Sameh Gaawan ◽  
Ashraf Osman
Keyword(s):  
Finite Element ◽  
Parametric Study ◽  
Thickness Ratio ◽  
Finite Element Models ◽  
T Joints ◽  
Hollow Section ◽  
Axial Strength ◽  
Structural Joints ◽  
Circular Hollow Section ◽  
Steel Design

In steel design, enhancing the structural joints’ capacity is considered a challenge that faces the designer. This challenge becomes more difficult when it comes to enhancing the capacities of circular hollow section (CHS) joints due to their closed nature that complicates the strengthening process. Recent research related to strengthening T-joints by utilizing two outer hollow ring flanges welded to additional pipe showed that this technique can significantly improve the joints’ strength. In this study, the utilization of this technique is extended for enhancing the axial strength of CHS X-joints. In this regard, a parametric study using finite element models was carried out to investigate the different design aspects that might affect the behavior of strengthened X-joints. The examined parameters included, the ring flange diameter, the stiffening pipe thickness and length for different brace diameter-to-chord diameter ratios and chord diameter to double chord thickness ratio. The results demonstrated that these strengthened X-joints gained significant axial strength that reached up to three times the axial strength of the unstrengthened joints. Guidelines for proper detailing of such strengthening scheme were provided. Finally, an equation that estimates the axial strength of strengthened joints was established based on the achieved results.

scholarly journals Numerical Analysis of Axial Cyclic Behavior of FRP Retrofitted CHS Joints

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 648
Author(s):  
Mohammad Alembagheri ◽  
Maria Rashidi ◽  
Amin Yazdi ◽  
Bijan Samali
Keyword(s):  
Numerical Analysis ◽  
Welding Process ◽  
Axial Loading ◽  
Cyclic Behavior ◽  
Buckling Mode ◽  
Compression Load ◽  
Hollow Section ◽  
Plastic Failure ◽  
Frp Composite ◽  
Circular Hollow Section

This paper aims to numerically investigate the cyclic behavior of retrofitted and non-retrofitted circular hollow section (CHS) T-joints under axial loading. Different joints with varying ratios of brace to chord radius are studied. The effects of welding process on buckling instability of the joints in compression and the plastic failure in tension are considered. The finite element method is employed for numerical analysis, and the SAC protocol is considered as cyclic loading scheme. The CHS joints are retrofitted with different numbers of Fiber Reinforced Polymer (FRP) layers with varying orientation. The results show that the welding process significantly increases the plastic failure potential. The chord ovalization is the dominant common buckling mode under the compression load. However, it is possible to increase the energy dissipation of the joints by utilizing FRP composite through changing the buckling mode to the brace overall buckling.

Experimental study on the axial compressive strength of vertical inner plate reinforced square hollow section T-joints

2018 ◽  
Vol 172 ◽  
pp. 131-140 ◽  
Author(s):  
Hongfei Chang ◽  
Junwu Xia ◽  
Zhen Guo ◽  
Chao Hou ◽  
Wei Din ◽  
...  
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
T Joints ◽  
Hollow Section ◽  
Axial Compressive Strength

scholarly journals Experimental Study on the Static Behavior of Reinforced Warren Circular Hollow Section (CHS) Tubular Trusses

2018 ◽  
Vol 8 (11) ◽  
pp. 2237 ◽  
Author(s):  
Wenwei Yang ◽  
Jiankang Lin ◽  
Ni-na Gao ◽  
Ruhao Yan
Keyword(s):  
Experimental Study ◽  
Carrying Capacity ◽  
Truss Structures ◽  
Load Carrying Capacity ◽  
Static Behavior ◽  
Hollow Section ◽  
Surface Plasticity ◽  
Load Carrying ◽  
Circular Hollow Section ◽  
Chord Member

For truss structures, the question of whether to weld hidden welds or not has been controversial. In the actual construction process of truss structures, the members are usually spot welded in place on the assembly platform, and then welded as a whole, while the hidden welds of the truss are not welded, especially for small pipe diameter trusses. Furthermore, in this study, under hidden weld unwelded conditions, two kinds of reinforcing method (adding a half outer sleeve on each joint and filling concrete into the chord members) are adopted to achieve the purpose of strengthening the truss. Therefore, this paper presents an experimental study on the static behavior of four types of Warren tubular trusses made of CHS members. These four types are (1) T-HW: The truss with hidden welds welded; (2) T-HN: The truss with hidden welds unwelded; (3) TS-AS: The truss strengthened on the basis of T-HN by adding a half outer sleeve on each joint; (4) TS-FC: The truss strengthened on the basis of T-HN by filling concrete into the top and bottom chord members. The mechanical behavior, failure mode, bearing capacity, and load-displacement of all specimens were investigated. The surface plasticity of the bottom chord member, the weld fracture around tubular joints at the bottom chord member, and the bending deformation of the bottom chord member were observed in the tests. Compared with the T-HW specimen, the load carrying capacity of the T-HN specimen decreased by 18%. On the other hand, the T-HN specimen has better deformability than the T-HW specimen. The reinforcing method of adding a half outer sleeve on each joint and filling concrete into the chord members can effectively improve the load carrying capacity and stiffness of the truss, thus reducing the overall deformation of the truss, but the reinforcing method of filling concrete into the chord members is more efficient.

Sign in / Sign up

Export Citation Format

Share Document