Most previous welding simulations are based on a flat weld pool surface and become unmeaningful when the surface deformation is significant. In recent years, some researchers have developed numerical models capable of simulating free surface motion in welding processes, but they focus on the discussions of physical equations, boundary conditions, and solutions, rather than the numerical algorit...

Welding processes are one of the most widely spread industrial activities, and their quality control is an important area of research. The presence of residual traces from the protective antioxidant coating, is a problematic issue since it causes a significant reduction in the welding seam strength. In this work, a solution based on a Laser Induced Breakdown Spectroscopy (LIBS) setup and a Supp...

introduction: the aim of this study was to investigate the morphological changes of human dentin after erbium-doped yttrium aluminum garnet (er:yag), carbon dioxide (co2) laser-irradiation and acid-etching by means of scanning electron microscopic (sem) m ethods: 9 extracted human third molars were used in this study. the teeth were divided in three groups: first group, co2 laser with power of ...

Cutting or welding heavy metal requires higher laser output power than virtually any other type of materials processing application. In the oil industry, an important heavy metal cutting application is creating the slotted liners used to separate oil from well sediments such as sand and gravel. Traditionally, this was done with diffusion-cooled CO2 slab lasers, but now, kilowatt-class fiber las...

introduction :   co 2 (carbon dioxide) laser application in circumcision, for cutting and coagulation, has been reported to have excellent results. also, tissue glue has been reported to have advantages over sutures for approximation of wound edges. most previous studies focused on comparisons between co 2 laser and scalpel, or between tissue glue and sutures. this study prospectively compared ...

This study is focused on the characterization of particles emitted in the metal active gas welding of carbon steel using mixture of Ar + CO2, and intends to analyze which are the main process parameters that influence the emission itself. It was found that the amount of emitted particles (measured by particle number and alveolar deposited surface area) are clearly dependent on the distance to t...

Automation of welding process in shipyard is ultimately necessary, since welding site is spatially enclosed by jloors and girders, and therefore welding operators are exposed to hostile working conditions. To solve this problem, recently a robotic welding system f o r closed block assembly has been developed. For complete autonomy, this system needs a sensor system for the weld seam tracking an...

Simplified fatigue and fracture mechanics based assessment methods are widely used by the industry to determine the structural integrity significance of postulated cracks, manufacturing flaws, service-induced cracking or suspected degradation of engineering components under normal and abnormal service loads. In many cases, welded joints are the regions most likely to contain original fabricatio...