A comprehensive mathematical model of the hot extrusion process for aluminum alloys has been developed and validated. The plasticity module was developed using a commercial finite element package, DEFORM-2D, a transient Lagrangian model which couples the thermal and deformation phenomena. Validation of the model against industrial data indicated that it gave excellent predictions of the pressur...

This paper describes a technique for determining the position of the friction stir welding (FSW) tool with respect to the weld seam during welding. This technique is proposed for online misalignment detection or as a position estimator for in-process tracking of the weld seam for FSW.

A new finite element based method for fatigue life prediction has been examined. The method uses nodal forces and moments along the weld toe to define a structural stress perpendicular to the weld. The method was found to be less mesh-sensitive than ordinarie post-processing.

The purpose of this study was to investigate the difference between tungsten inert gas (TIG) welding of austenitic stainless steel assisted by microparticle oxides and that assisted by nanoparticle oxides. SiO₂ and Al₂O₃ were used to investigate the effects of the thermal stability and the particle size of the activated compounds on the surface appearance, geometric shape, angular distortion, d...

The objective of the work consists in the design and implementation of techniques of automatic recognition of weld regions. It is aimed to complete a system of automatic inspection of radiographic images of welded joints. It deals with the problem of the delimitation of the weld regions according to the general scheme of image interpretation systems based on knowledge.

This thesis presents a collection of theoretical and experimental investigations into various geometrical aspects of hybrid laser-MIG welding. The work is divided up into four parts; 1. A review of the hybrid laser-MIG welding technique with brief summaries of the three papers which make up the remainder of the thesis. 2. A paper entitled “Fundamental analysis of hybrid laser-MIG welding”. This...

Underwater wet welding is one of the most common repair measures for corroded offshore steel structures. Few studies have been carried out systematically concerned with mechanical properties of such welds, thus current design provisions rely heavily on limited experimental data on welds made underwater and design properties for corresponding welds made in air. This paper presents a series of ex...

The welding of materials by applying Friction Stir Welding technique is a new solid-state joining technique. The main advantage of this method compared to the traditional joining process is that it minimizes problem-related to metal resolidification as the method incorporates no melting phase. In this experimental work, the effect of friction stir welding (FSW) technique on the microstructu...

The radiography technique (RT) used in non-destructive testing (NDT) of welds has evolved rapidly in recent decades and has become an established technology in the field of weld assessment. RT is widely used as an inspection tool for detecting flaws inside welded structures, pressure vessels, structural members and pipelines(1). Most radiographic exposures and film interpretations in RT are sti...