Search results for "T-joint"

Friction Stir Welding of Ti6Al4V complex geometries for aeronautical applications: a feasibility study

2020

Abstract While Friction Stir Welding (FSW) of aluminium alloys can be considered a mature technology, even for complex joint morphologies, as T joints welded “in transparency”, welding of hard material still presents several open issues. In fact, welding of titanium alloys is a challenging process due to the chemical, mechanical and thermal characteristics of such materials which are subjected to atmosphere contamination resulting in joint hydrogen, oxygen and nitrogen embrittlement; additionally, due to the high melting temperature, large distortion and residual stress are found in joints obtained by traditional fusion welding processes as gas metal arc welding, electron beam welding and l…

A New Friction Stir Welding Based Technique for Corner Fillet Joints: Experimental and Numerical Study

2010

Friction stir welding (FSW) is an energy efficient and environmentally "friendly" (no fumes, noise, or sparks) welding process, during which the sheets are welded together in a solid-state joining process. FSW is mature for simple configurations but a significant lack of knowledge is found when dealing with different designs such as T-sections, corner welds and box sections. The present work explores the feasibility of producing corner fillet geometries using FSW. Although such a kind of geometry has traditionally been considered unfeasible for the process, it seems to have a great potential to be used for T-joint configurations, a recurrent design pattern in transport applications. A speci…

On the material flow in fsw of T-joints: influence of geometrical and tecnological parameters

2008

Friction stir welding (FSW) now definitively reached a large interest in the scientific community and what is more in the industrial environment, due to the advantages of such solid state welding process with respect to the classic ones. The latter aspects are relevant also with reference to joints characterized by a complex geometry. What is more, advanced FEM tools permit to develop effective engineering of the processes; quantitative results can be acquired from numerical simulations once basic information, as the process mechanics and the material flow, are certain. Material flow plays a fundamental role in FSW since it determines the effectiveness of the joints or, in turn, the insurge…

Material Flow in FSW of T-joints: Experimental and Numerical Analysis

2008

In the paper the authors present the results of both an experimental and a numerical campaign focused on the analysis of the occurring material flow in the FSW of T joints of aluminum alloys. In particular to investigate the metal flow experimental tests and observations has been developed utilizing a thin foil of copper as marker placed between the skin and the stringer. In this way, the actual metal flow occurring during the FSW of T-joints has been highlighted together with the real bonding surface. The acquired information is definitively useful in order to choose effective set of process parameters, improving the process mechanics and avoiding the insurgence of defects.

Development of corner fillet joints using friction stir welding

2010

Experimental Characterization of FSW T-Joints of Light Alloys

2007

Welding is playing a growing role in transport industry due to relevant advantages it allows. Friction Stir Welding is considered one of the most promising joining technologies, especially when it is applied to light alloys. Focusing attention on FSW of T-joints, several parameters have to be considered, and due to thermo-mechanical features of process, T joints need a dedicated approach. A set of previously developed experiments has shown that the tilt angle plays a relevant role in the joint strength. Furthermore it should be observed that T-joints are very often utilized in aerospace industries since the produced structures are composed of joined skins and stingers. Numerous data are rep…

Residual stress and material flow prediction in Friction Stir Welding of Gr2 Titanium T-joints

2022

Friction Stir Welding is nowadays an established technique successfully used by many industries. However, most of the research and, consequently, most of the applications regard aluminum alloys and butt joints. T-joints are of high interest for different industrial sectors as aeronautical, aerospace, naval and ground transportation, for which joint integrity and low residual stress are extremely important. In this study, an experimental and numerical approach is proposed with the aim to study the peculiarities of the residual stress distribution and material flow occurring in FSW of CP-Ti T-joints. Experiments were carried out to assess the feasibility of the process and to acquire the temp…

Outcomes After Chevron Osteotomy with and Without Additional Akin Osteotomy: A Retrospective Comparative Study

2023

Abstract Background Chevron osteotomy is one of the most common approaches to hallux valgus corrective surgery. This procedure is often combined with Akin osteotomy of the proximal phalanx of the hallux. There are no definitive guidelines specifying the indications for a given osteotomy technique nor data on postoperative loss of correction or the effect of the type of first-ray surgery on the development of adjacent-joint arthritis. The aim of this study was to assess radiographic treatment outcomes via chevron osteotomy with and without Akin osteotomy. Methods The study evaluated 117 patients treated in the period 2016–2019. Ninety-nine of those patients underwent distal chevron osteotomy…

Influence of material characteristics on plastomechanics of the fsw process for T-joints

2009

Abstract The potential of friction stir welding (FSW) has thoroughly been investigated by several authors, however their focus has primarily been on butt joints. T-joints are of paramount interest for transportation industries especially due to their capacity to straighten panels. Welding of T-joints is very challenging due to thin walls, poor location of the rib–web interface and the requirements for corner-fillets. This paper investigates FSW of T-joints of two popular aluminum alloys, i.e. 2024-T4 and 6082-T6, and the role played by the material characteristics on joining. First, an experimental study is carried out with specially designed fixture to determine the effect of process condi…

Radiographic Outcomes of Hallux Valgus Deformity Correction With Chevron and Scarf Osteotomies

2023

There is no gold standard in the treatment of hallux valgus deformity. The purpose of our study was to compare various aspects of radiographic assessment following scarf and chevron osteotomies and try to determine which technique helps achieve a more pronounced intermetatarsal angle (IMA) and hallux valgus angle (HVA) correction and produces lower rates of complications, including adjacent-joint arthritis. This study included patients who underwent hallux valgus correction with the scarf (n = 32) or chevron (n = 181) method with a follow-up period of over 3 years. We evaluated the following parameters: HVA, IMA, duration of hospital stay, complications, development of adjacent-joint arthri…