[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Recent advances in friction-stir welding : Process, weldment structure and properties

Mechanically alloyed nanocomposites

nonlinear finite elements for continua and structures is available in our book collection an online access to it is set as public so you can get it instantly. Our books collection saves in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Kindly say, the nonlinear finite elements for continua and structures is universally compatible with any devices to read.

Nonlinear Finite Elements For Continua And Structures

In this investigation an attempt has been made to understand the mechanism of friction stir weld formation and the role of friction stir welding tool in it. This has been done by understanding the material flow pattern in the weld produced in a special experiment, where the interaction of the friction stir welding tool with the base material is continuously increased. The results show that there are two different modes of material flow regimes involved in the friction stir weld formation; namely “pin-driven flow” and “shoulder-driven flow”. These material flow regimes merge together to form a defect-free weld. The etching contrast in these regimes gives rise to onion ring pattern in friction stir welds. In addition to that based on the material flow characteristics a mechanism of weld formation is proposed.

The role of friction stir welding tool on material flow and weld formation

Strains and strain rates during friction stir welding

Numerical studies on controlling of process parameters in friction stir welding

3D modeling of material flow in friction stir welding under different process parameters

Solid mechanics-based finite element models and computational procedures are developed to study the flow patterns and the residual stresses in frictional stir welding (FSW). Two-dimensional results of the material flow patterns and the residual stresses are presented. The flow of metal during FSW is investigated using tracer particles. It is shown that the flows on the advancing side and retreating side are different. After several rotations the material which is rotating around the nib sloughs off in its wake of the pin, primarily on the advancing side. The residual stresses of the welded plate are investigated in this analysis. The distribution of the longitudinal residual stress along the direction perpendicular to the welding line is a double feature curve. With the increase of the translational velocity, the maximum longitudinal residual stress can be increased.

The finite element simulation of the friction stir welding process

This paper presents a new developed fully coupled thermo-mechanical model of the friction stir welding process. Results indicate that the rotation of the shoulder can accelerate the material flow behavior near the top surface. The material deformation and the temperature field can have relations with the microstructural evolution. The texture of the appearance of the friction stir welds can correlate well with the equivalent plastic strain distributions on the top surface. The temperature field in the friction stir welding process is approximately symmetric to the welding line. The material flows in different thicknesses are different. The shoulder can have a significant effect on material behaviors on the top surface, but this effect is greatly weakened when the material gets closer to the bottom surface of the welding plate.

Zhao Zhang

Papers

Strains and strain rates during friction stir welding

Numerical studies on controlling of process parameters in friction stir welding

3D modeling of material flow in friction stir welding under different process parameters

The finite element simulation of the friction stir welding process

A fully coupled thermo-mechanical model of friction stir welding