فهرست مقالات Welding Process

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  1 - Evaluation of S/N Diagram in Welded Joints Based on Different Fatigue Failure Criteria
  Saeed Jouzdani Ali Heidari
  10.30495/admt.2020.1885273.1164
  One of the most important problems in the welded Joints is the low fatigue strength due to the residual stresses. Purpose of this study is to investigate the effect of residual stresses on S/N diagram of the welded joints. For this purpose, welding process of two plates چکیده کامل

  One of the most important problems in the welded Joints is the low fatigue strength due to the residual stresses. Purpose of this study is to investigate the effect of residual stresses on S/N diagram of the welded joints. For this purpose, welding process of two plates is firstly modeled on a precise and three-dimensional model. This simulation has been carried out in two non-coupled thermal-mechanical steps, including the birth and death of elements technique, presence of molten flow inside melting pool and latent heat generated by phase transformations in the simulator program. Thermal and mechanical results of the program are compared with numerical and experimental results of other researchers, which indicates acceptable accuracy of the program. In the next step, effect of welding process residual stress on S/N diagram is investigated with two different fatigue criteria, which the results indicate a decrease in the fatigue strength. Goodman's modified fatigue criterion shows 88%, and Gerber's criterion shows 78% of reduction. Finally, by examining effect of changes in air flow parameters and preheating, the results showed that the transient air flow reduced fatigue strength for 5% and preheating, results in a 9% increase in fatigue strength. پرونده مقاله
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  2 - Thermal and Stress Analysis in Butt, T-shaped and Tubular Joints in the Welding Process of Dissimilar Parts
  Adel Tavabe Behdad Jahanbeen Seyed Mohammad Reza Nazemosadat Ahmad Afsari
  Connecting parts through welding as permanent connections can play an important role in various industries. Despite the favorable load-bearing capabilities of joints resulting from welding dissimilar parts, they have some limitations that need to be identified and check چکیده کامل

  Connecting parts through welding as permanent connections can play an important role in various industries. Despite the favorable load-bearing capabilities of joints resulting from welding dissimilar parts, they have some limitations that need to be identified and checked to optimize their use. One of the limitations is the behavior of parts under thermal stresses caused by the welding process. Thus, it is important to consider the welding conditions of the dissimilar parts in the contact area of the electrode and the welding seam, as this can significantly affect the mechanical performance of the welds. The research conducted in this study involved using the electric welding method with non-consumable tungsten electrodes under shielding gas (TIG) to connect aluminum and carbon steel parts. Ansys software was utilized to investigate the effect of thermal stress in the welding process for different joints. To ensure accuracy, parts were welded together practically under similar conditions, and the results obtained were compared with the results of the modeled method. First, the behavior of a steel sheet under the butt and Tee Joint and then the role of various factors on welding performance were investigated by modeling the process for a pipe in different conditions. Finally, due to the significant role of T-shaped joints in various industries, heat distribution, behavior, and stress analysis were investigated. پرونده مقاله
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  3 - An Initiative Plan of the Equivalent Model for Simulation of theWelding Process
  علی حیدری محمدرضا فروزان جعفر گلستانه
  Many researchers content themselves with the 2D simulation of welding process instead of the 3D simulation, because of the time and the cost factors of the latter. In this research, the number of elements and nodes are reduced by an initiative plan (defining an equivale چکیده کامل

  Many researchers content themselves with the 2D simulation of welding process instead of the 3D simulation, because of the time and the cost factors of the latter. In this research, the number of elements and nodes are reduced by an initiative plan (defining an equivalent model) for the simulation of welding. The welding process has been simulated by an uncoupled thermal-mechanical finite element model in three steps. Thermal history was determined from thermal analysis, and then the distribution of the metallurgical phase on the fusion and heat affected zones were calculated by a certain code. Afterward, the stress distribution was computed from mechanical analysis, where the material property was defined element by element according to the second step. One of the most important objectives of this simulation is to study the residual stresses of welding. Comparisons between the thermal analysis results and the metallographic and laboratory results of this research show acceptable accuracy of the proposed method. پرونده مقاله