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.

scholarly journals Buckling Behavior of Non-Retrofitted and FRP-Retrofitted Steel CHS T-Joints

2021 ◽  
Vol 11 (7) ◽  
pp. 3098
Author(s):  
Amin Yazdi ◽  
Maria Rashidi ◽  
Mohammad Alembagheri ◽  
Bijan Samali
Keyword(s):  
Compressive Loading ◽  
Local Buckling ◽  
Buckling Mode ◽  
T Joints ◽  
Hollow Section ◽  
Frp Composite ◽  
Buckling Behavior ◽  
Global Buckling ◽  
Post Buckling ◽  
Circular Hollow Section

This paper aims to investigate the buckling behavior of circular hollow section (CHS) T-joints in retrofitted and non-retrofitted states under axial brace compressive loading. For this purpose, two types of analysis are carried out. The first one is evaluating the critical buckling load in various tubular joints, and the other one is investigating the post-buckling behavior after each buckling mode. More than 180 CHS T-joints with various normalized geometric properties were numerically modeled in non-retrofitted state to compute their governing buckling mode, i.e., chord ovalization, brace local, or global buckling. Then three joints with different buckling modes were selected to be retrofitted by fiber-reinforced polymer (FRP) patches to illustrate the improving effect of the FRP wrapping on the post-buckling performance of the retrofitted joints. In addition, FRP composite failures were investigated. The results indicate that the FRP retrofitting is able to prevent the brace local buckling, and that matrix failure is the most common composite failure in the retrofitted joints.

Numerical Simulation of Welding Induced Residual Stresses in a Circular Hollow Section T-Joint

2006 ◽  
Author(s):  
Suraj Joshi ◽  
Cumali Semetay ◽  
John W. H. Price ◽  
Herman Nied
Keyword(s):  
Residual Stresses ◽  
Cross Sections ◽  
Mining Industry ◽  
Welding Process ◽  
Civil Structures ◽  
Element Analysis ◽  
Hollow Section ◽  
3 Dimensional ◽  
Circular Hollow Section ◽  
Intense Heat

Heavily welded circular hollow cross sections (CHS) are a common feature in civil structures such as draglines used in the mining industry and other off-shore structures. The sheer mass of the weldment and the application of intense heat generated during the welding process give birth to significant residual stresses in the structure. Often, residual stresses are high enough to act to accelerate factors such as corrosion, crack growth and fatigue. The objective of this research investigation was to predict welding generated residual stresses in a typical CHS T-Joint using Sysweld+, a welding Finite Element Analysis software. The T-joint is the first of the four lacings welded on to the main chord of a BE 1370 mining dragline cluster (designated All) of a type which is often used in the mining industry in Australia. This work examines a massive 3-dimensional geometry, which is on a much larger scale than those examined in existing studies. The paper presents the results of the simulation of residual stresses generated during the welding process in a single weld pass and compares them with the approach used in the commonly used document R6-Revision 4, Assessment of the Integrity of Structures Containing Defects.

Parametric Study of Static Strength of Multiplanar KK-Joints：Square Chords and Circular Braces

2011 ◽  
Vol 250-253 ◽  
pp. 1527-1532
Author(s):  
Ai Guo Chen ◽  
Wei Liang Huang ◽  
Rui Zeng Shan ◽  
Qing Shan Yang
Keyword(s):  
Parametric Study ◽  
Large Scale ◽  
Failure Modes ◽  
Numerical Models ◽  
Axial Loading ◽  
Steel Structure ◽  
Geometric Parameters ◽  
Truss Structures ◽  
Hollow Section ◽  
Circular Hollow Section

Pre-stressed spatial tubular truss system is adopted in steel roof truss structures of China International Exhibition Center New Venue. Bottom chord joints are multiplanar KK-joints consisting of chord with square hollow section and brace with circular hollow section. However, not only that relatively little research has been carried out on such joints, but also that no detailed design guidance on KK-type joints consisting of chord with square hollow section and brace with circular hollow section can be found Current design code for steel structure (GB 50017-2003). This paper reports the study into the strength of this type of KK-joints under axial loading. The numerical models were adopted, and several various geometric parameters which affect the strength and failure modes, were investigated. It was indicated that the geometric parameters affects significantly the ultimate capacity and failure modes of the joints. The varied relationship of the strength and failure mode with parameter varying was studied in detail. The results of the work presented provide initial discussion on behavior of this type of KK-joints and lay the foundation for a future large-scale parametric study and put out design formula.

scholarly journals Ultimate Axial Strength of Concrete-Filled Double Skin Steel Tubular Column Sections

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
S. İpek ◽  
E. M. Güneyisi
Keyword(s):  
Gene Expression Programming ◽  
Estimation Error ◽  
Axial Loading ◽  
Steel Tubes ◽  
Hollow Section ◽  
Composite Columns ◽  
Axial Strength ◽  
Proposed Model ◽  
Double Skin ◽  
Circular Hollow Section

This study aims at proposing a new model for evaluating the ultimate axial strength of concrete-filled double skin steel tubular (CFDST) composite columns. For this, a total of 103 experimental data regarding the ultimate strength of CFDST columns under axial loading were collected from the previous studies in the literature. All CFDST columns consist of two steel tubes being outer and inner circular hollow section. The model presented herein was developed by using gene expression programming. For this, the yield strength, diameter, and thickness of both outer and inner steel tubes, the compressive strength of annulus concrete, the length of the specimen, and the ultimate axial strength of the columns were utilized as the parameters. Assessment of the obtained results indicated that the generated model had a good performance compared to the existing models by the previous researchers and the equations specified in the design codes. The high value of R2 and narrow ranged fluctuation of the estimation error for the ultimate axial strength of the CFDST columns were also achieved through the proposed model.

Numerical analysis of circular hollow section bolted sleeve connection

2016 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Rodrigo Cuberos Vieira ◽  
João Alberto Venegas Requena ◽  
Arlene Maria Sarmanho ◽  
Afonso Henrique Mascarenhas de Araújo
Keyword(s):  
Numerical Analysis ◽  
Hollow Section ◽  
Circular Hollow Section

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 the Ultimate Bearing Capacity of Partially Overlapped CHS-to-SHS Welded N-Joints

2011 ◽  
Vol 368-373 ◽  
pp. 473-477
Author(s):  
Xing Ping Shu ◽  
Zhi Shen Yuan ◽  
Zheng Rong Zhu ◽  
Yao Yao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bearing Capacity ◽  
Failure Mode ◽  
Side Wall ◽  
Axial Loading ◽  
Ultimate Bearing Capacity ◽  
Element Analysis ◽  
Hollow Section ◽  
Circular Hollow Section

This paper presents the experimental and numerical results of the ultimate bearing capacity of partially overlapped tubular N-joints, which have circular hollow section (CHS) brace members welded to a square hollow section (SHS) chord member. Two partially overlapped N-joints were tested to failure under overlapping brace axial loading and chord axial loading. The failure mode of specimen N1 was the overlapping brace local bucking, and the failure mode of specimen N2 was the chord face plastification with chord side wall buckling. Meanwhile, weld fracture occurred on both specimens. Then, making use of finite element package program ANSYS, in which twenty nodes solid element was employed and the weld was simulated, elastic-plastic large deflection finite element analysis of the experimental joints was conducted. The experimental data were compared with the results acquired by finite element analysis and it was proved that ANSYS is feasible to simulate the connecting weld and analyze the static behavior of partially overlapped CHS-to-SHS welded N-joints.

scholarly journals Durability of CFRP strengthened steel circular hollow section member exposed to sea water

2016 ◽  
Vol 118 ◽  
pp. 216-225 ◽  
Author(s):  
M.H. Kabir ◽  
S. Fawzia ◽  
T.H.T. Chan ◽  
M. Badawi
Keyword(s):  
Sea Water ◽  
Hollow Section ◽  
Circular Hollow Section
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