جستجوی مقالات مرتبط با کلیدواژه "fsw" در نشریات گروه "مکانیک"

Temperature prediction is essential for assessing the state of stresses, strains, and material flow during friction stir welding (FSW). In this context, the thermal and mechanical behavior of the AA6063-T5 aluminum alloy was simulated in FSW. This research utilized the Finite Element Method (FEM) for thermal and mechanical simulations, employing Abaqus/Explicit software. The first simulation focused on the thermal model, implemented through coding in FORTRAN using the Schmidt-Hotel reference model, which investigates the temperature distribution of the alloy. The second simulation was mechanical in nature; it utilized the output results from the thermal simulation to examine the stresses resulting from the FSW process. The samples were made of the same material and were butt-jointed for the operation. A tool speed of 60 mm/min, a force of 4000 newtons, and a coefficient of friction of 0.4 were applied during this process. The parameters for thermal conductivity, specific heat, coefficient of expansion, and Young's modulus were defined as temperature-dependent. The results indicated that the temperature distribution diagram at a specific point along the welding path closely matched practical examples of the FSW process. The temperature distribution contours at the beginning, middle, and end of the welding path, as well as the temperature distribution across the cross-sectional surface of the weld in the middle of the piece, were consistent with the samples. Additionally, the diagram and contour of the longitudinal residual stress in the workpiece aligned well with the completed samples.

This study aimed to investigate the influence of rotational and traverse speeds on the friction stir welding (FSW) of aerospace-grade aluminum alloys. To achieve this, a thermo-mechanically coupled 3D finite element analysis (FEM) was employed to analyze the impact of these speeds on temperature and strain. Additionally, tensile tests were conducted on welded joints fabricated using varying tool rotational and traverse speeds to examine the effects of welding speed on the tensile properties of the specimens. The results revealed that high welding speeds had a detrimental effect on the mechanical properties of the weld samples. Samples produced using an optimal rotational speed of 1200 rpm and a traverse speed of 40 mm exhibited a tensile strength of 346 MPa, which accounts for approximately 64% of the strength seen in the base material.

Friction Stir Welding has significantly transformed the metal joining industry, and an innovative variation known as stationary shoulder FSW has emerged. This study aimed to compare various aspects, including force, temperature, and strain, between conventional friction stir welding (CFSW) and stationary shoulder friction stir welding (SSFSW). To accomplish this, the finite element method was employed, utilizing the lagrangian technique to model the welding process. The findings revealed that in SSFSW, the highest temperature was observed in the vicinity of the rotating pin. This was attributed to the absence of a rotating shoulder in SSFSW, which played a major role in heat generation during welding. Moreover, the longitudinal forces on the tool in SSFSW were significantly higher compared to CFSW, approximately ten times greater. In the CFSW process, the affected area showing strain usually forms a basin-shaped pattern. However, in the SSFSW process, the strain distribution is confined within the range of the tool pin.