scholarly journals Behaviour of Steel Tubular Knee Joint in Aluminium Frames with Tension-Tie Element

2020 ◽  
Vol 11 (1) ◽  
pp. 70
Author(s):  
Davor Skejić ◽  
Ivan Čudina ◽  
Ivica Garašić ◽  
Federico M. Mazzolani
Keyword(s):  
Knee Joint ◽  
Failure Modes ◽  
Numerical Study ◽  
Knee Joints ◽  
Flexural Behaviour ◽  
Welded Steel ◽  
Reliable Assessment ◽  
Joint Behaviour ◽  
Steel Joints ◽  
Rotation Behaviour

Aluminium portal frames with a tension tie element are a commonly used type of aluminium structure. Due to the significant reduction in aluminium’s mechanical properties caused by welding, typical beam to column joints of such frames are formed using bolts and welded steel knee joints embedded in the structure. Expressions for the reliable assessment of the behaviour of such joints are lacking, thus limiting the use of aluminium portal frames. Although the behaviour of steel joints using hollow sections is well investigated, there are only a small number of studies regarding knee joints, none of which investigate the influence of the tie element on the joint behaviour. Therefore, the first stage of the research is focused on the flexural behaviour of steel knee joints with tension tie elements. Laboratory tests of three identical steel knee joints with a tension tie element were conducted as well as a parametric numerical study with variation of tie element stiffness. It was concluded that different stiffnesses of the tie element have little influence on moment–rotation behaviour of the knee joint, but greatly affect overall frame resistance to vertical loads. It was also concluded that different stiffnesses of the tie element can lead to different failure modes of the knee joint as well.

Preliminary Parametric Assessment of a Bolted Endplate Joint under Combined Axial Force and Cyclic Bending Moment

2011 ◽  
Vol 255-260 ◽  
pp. 718-721
Author(s):  
Z.Y. Wang ◽  
Q.Y. Wang
Keyword(s):  
Finite Element Analysis ◽  
Axial Force ◽  
Seismic Design ◽  
Axial Load ◽  
Failure Modes ◽  
Bending Moment ◽  
Element Analysis ◽  
Cyclic Behaviour ◽  
Joint Behaviour ◽  
Steel Joints

Problems regarding the combined axial force and bending moment for the behaviour of semi-rigid steel joints under service loading have been recognized in recent studies. As an extended research on the cyclic behaviour of a bolted endplate joint, this study is performed relating to the contribution of column axial force on the cyclic behaviour of the joint. Using finite element analysis, the deteriorations of the joint performance have been evaluated. The preliminary parametric study of the joint is conducted with the consideration of flexibility of the column flange. The column axial force was observed to significantly influence the joint behaviour when the bending of the column flange dominates the failure modes. The reductions of moment resistance predicted by numerical analysis have been compared with codified suggestions. Comments have been made for further consideration of the influence of column axial load in seismic design of bolted endplate joints.

Performance of Unstiffened Welded Steel I-Beam to Hollow Tubular Column Connections Under Seismic Loading

2015 ◽  
Vol 15 (01) ◽  
pp. 1450033 ◽  
Author(s):  
Qian-Yi Song ◽  
Amin Heidarpour ◽  
Xiao-Ling Zhao ◽  
Lin-Hai Han
Keyword(s):  
Cyclic Loading ◽  
Failure Modes ◽  
Numerical Study ◽  
Combined Loading ◽  
Building Structures ◽  
Welded Steel ◽  
Damage Level ◽  
Tubular Columns ◽  
Steel Connections ◽  
Static And Cyclic Loading

Earthquake causes wide and severe damage to building structures, due to not just the great ground motion but also secondary actions, such as impact, blast or fire, occurring after earthquake. The extreme combined loading scenario should be considered for safety of buildings and lives. Taking fire for example, the combined load can be considered as an event in which the structures are first partially damaged under an earthquake and then attacked by fire. In order to investigate the post-earthquake loading scenario, it is important to assess the partial damage caused by earthquake on different components of structures. The behavior of welded steel I-beam to hollow square tubular columns is investigated herein. A detailed experimental study is presented in which two groups of unstiffened welded steel connections, with the same configurations, subjected to static and cyclic loading are considered. The flexibility and strength of the connections are measured, while the damage phenomena and failure modes are explored during the tests. The connection damage is found to be a cumulative fracture developing process which leads to significant gradual degradation of the mechanical properties of the connection. The quantificational evaluations of the cyclic loading induced damage are also carried out to investigate the connection damage level according to different loading intensities. A finite element modeling numerical study is also carried out to validate the experimental results and a good agreement is achieved. The test results and FE modeling provide a benchmark data for the unstiffened welded connections and can be used for further investigations of the connections subjected to combined actions such as post-earthquake fire.

scholarly journals Experimental and Numerical Study of Mechanical Behavior of Welded Steel Plate Joints

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1293
Author(s):  
Hongwei Ma ◽  
Hao Zheng ◽  
Wei Zhang ◽  
Zhanzhan Tang ◽  
Eric M. Lui
Keyword(s):  
Mechanical Behavior ◽  
Failure Modes ◽  
Steel Plate ◽  
Numerical Study ◽  
Damage Model ◽  
Hysteretic Behavior ◽  
Cyclic Loads ◽  
Welded Steel ◽  
Damage Process ◽  
Monotonic Loads

This paper describes a study of welded steel plate joints using experimental and numerical methods. The objectives of this study are to observe the mechanical behavior of welded plate joints under monotonic and cyclic loads, identify their damage degradation processes, and provide useful test data for future damage analysis of beam-column connections in steel frame structures. Six specimens were designed, of which three were tested under monotonic loads, and the other three were tested under cyclic loads. The test setup consisted of three plates arranged in a cruciform and connected by two groove welds. The monotonic and cyclic loads were applied to the free end of the two outstanding plates, inducing a pulling force on the welded joint. Because the only element studied in the present work is the weld, the sizes of the three plates were kept constant. The responses of these welded plate joints are discussed in terms of their experimentally and numerically obtained mechanical parameters, hysteretic behavior, strain variations, stiffness degradation, damage process, and failure modes. The results show that the energy damage model outperforms the displacement damage model in terms of indicating the degree of damage. Furthermore, if designed according to code, all these welded plate joints perform satisfactorily.

scholarly journals Design of haunches in structural steel joints

2017 ◽  
Vol 23 (6) ◽  
pp. 765-772 ◽  
Author(s):  
Marta KUREJKOVÁ ◽  
František WALD
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Structural Steel ◽  
Failure Modes ◽  
Numerical Study ◽  
Design Procedure ◽  
Element Model ◽  
Element Analysis ◽  
Simple Arrangement ◽  
Steel Joints

The paper presents research in design of haunches in structural steel joints. Experimental results of six speci­mens of haunches with and without flanges are presented. Three specimens are without flanges and three specimens are supported by additional flanges. Flanges differ in stiffness to observe the increase in haunch resistances and the effect on buckling shapes. The research finite element model (RFEA) is studied by material and geometrical nonlinear finite element analysis with imperfections under the actual stress conditions and validated on the measured experimental data. The validity is demonstrated on the comparison of load-deflection curves, failure modes, stress distributions and yield line patterns. The stability analysis of a joint with a haunch is related to the research into component based finite element models of complex joints. The input and the results of the research finite element model are summarised in a benchmark case of a haunch with a flange. A numerical study illustrates the effect of the flange stiffness on the joint’s resistance. The effect is demonstrated on a simple arrangement with triangular stiffeners and on a beam-to-column joint. The main goal of the research is to verify proposed design procedure for stiffeners in steel joints.

Visualization of Cartilage from Knee Joint Magnetic Resonance Images and Quantitative Assessment to Study the Effect of Age, Gender and Body Mass Index (BMI) in Progressive Osteoarthritis (OA)

2019 ◽  
Vol 15 (6) ◽  
pp. 565-572
Author(s):  
Mallikarjunaswamy Shivagangadharaiah Matada ◽  
Mallikarjun Sayabanna Holi ◽  
Rajesh Raman ◽  
Sujana Theja Jayaramu Suvarna
Keyword(s):  
Body Mass Index ◽  
Magnetic Resonance ◽  
Knee Joint ◽  
Body Mass ◽  
3D Visualization ◽  
Cartilage Degradation ◽  
Magnetic Resonance Images ◽  
Cartilage Thickness ◽  
Knee Joints ◽  
Data Set

Background: Osteoarthritis (OA) is a degenerative disease of joint cartilage affecting the elderly people around the world. Visualization and quantification of cartilage is very much essential for the assessment of OA and rehabilitation of the affected people. Magnetic Resonance Imaging (MRI) is the most widely used imaging modality in the treatment of knee joint diseases. But there are many challenges in proper visualization and quantification of articular cartilage using MRI. Volume rendering and 3D visualization can provide an overview of anatomy and disease condition of knee joint. In this work, cartilage is segmented from knee joint MRI, visualized in 3D using Volume of Interest (VOI) approach. Methods: Visualization of cartilage helps in the assessment of cartilage degradation in diseased knee joints. Cartilage thickness and volume were quantified using image processing techniques in OA affected knee joints. Statistical analysis is carried out on processed data set consisting of 110 of knee joints which include male (56) and female (54) of normal (22) and different stages of OA (88). The differences in thickness and volume of cartilage were observed in cartilage in groups based on age, gender and BMI in normal and progressive OA knee joints. Results: The results show that size and volume of cartilage are found to be significantly low in OA as compared to normal knee joints. The cartilage thickness and volume is significantly low for people with age 50 years and above and Body Mass Index (BMI) equal and greater than 25. Cartilage volume correlates with the progression of the disease and can be used for the evaluation of the response to therapies. Conclusion: The developed methods can be used as helping tool in the assessment of cartilage degradation in OA affected knee joint patients and treatment planning.

Flexural behaviour of hollow concrete beams under three points loading: Experimental and numerical study

Structures ◽  
2021 ◽  
Vol 32 ◽  
pp. 1543-1552
Author(s):  
A.S. Elamary ◽  
I.A. Sharaky ◽  
M. Alqurashi
Keyword(s):  
Concrete Beams ◽  
Numerical Study ◽  
Flexural Behaviour

scholarly journals Design and analysis of concrete-filled tubular flange girders under combined loading

2021 ◽  
pp. 136943322110015
Author(s):  
Rana Al-Dujele ◽  
Katherine Ann Cashell
Keyword(s):  
Finite Element ◽  
Axial Force ◽  
Failure Modes ◽  
Numerical Study ◽  
Combined Loading ◽  
Torsional Stiffness ◽  
Fe Model ◽  
Combined Effects ◽  
Element Analysis ◽  
Hollow Section

This paper is concerned with the behaviour of concrete-filled tubular flange girders (CFTFGs) under the combination of bending and tensile axial force. CFTFG is a relatively new structural solution comprising a steel beam in which the compression flange plate is replaced with a concrete-filled hollow section to create an efficient and effective load-carrying solution. These members have very high torsional stiffness and lateral torsional buckling strength in comparison with conventional steel I-girders of similar depth, width and steel weight and are there-fore capable of carrying very heavy loads over long spans. Current design codes do not explicitly include guidance for the design of these members, which are asymmetric in nature under the combined effects of tension and bending. The current paper presents a numerical study into the behaviour of CFTFGs under the combined effects of positive bending and axial tension. The study includes different loading combinations and the associated failure modes are identified and discussed. To facilitate this study, a finite element (FE) model is developed using the ABAQUS software which is capable of capturing both the geometric and material nonlinearities of the behaviour. Based on the results of finite element analysis, the moment–axial force interaction relationship is presented and a simplified equation is proposed for the design of CFTFGs under combined bending and tensile axial force.

Fatigue Behaviour of Friction Stir Welded Steel Joints

2014 ◽  
Vol 891-892 ◽  
pp. 1488-1493 ◽  
Author(s):  
José Azevedo ◽  
Virgínia Infante ◽  
Luisa Quintino ◽  
Jorge dos Santos
Keyword(s):  
Base Material ◽  
Welding Process ◽  
Steel Structures ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Welded Steel ◽  
Shipbuilding Industry ◽  
Friction Stir ◽  
Steel Joints

The development and application of friction stir welding (FSW) technology in steel structures in the shipbuilding industry provide an effective tool of achieving superior joint integrity especially where reliability and damage tolerance are of major concerns. Since the shipbuilding components are inevitably subjected to dynamic or cyclic stresses in services, the fatigue properties of the friction stir welded joints must be properly evaluated to ensure the safety and longevity. This research intends to fulfill a clear knowledge gap that exists nowadays and, as such, it is dedicated to the study of welded steel shipbuilding joints in GL-A36 steel, with 4 mm thick. The fatigue resistance of base material and four plates in as-welded condition (using several different parameters, tools and pre-welding conditions) were investigated. The joints culminate globally with defect-free welds, from which tensile, microhardness, and fatigue analyses were performed. The fatigue tests were carried out with a constant amplitude loading, a stress ratio of R=0.1 and frequency between 100 and 120 Hz. The experimental results show the quality of the welding process applied to steel GL-A36 which is reflected in the mechanical properties of joints tested.

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