Metal active gas (MAG) welding is one the most reliable procedures for joining various structural components. MAG is applied in many industries due to its low manufacturing cost and fast yet simple performance. While conducting this technique, a large amount of molten wire metal fills the groove between the structural components of the base material. As the heat input of the filler material is very high and its cooling rate is rapid afterwards, permanent plastic deformations and residual stresses occur in the weld area and its vicinity [1
]. The plastic deformations disturb the external appearance of the welded structure making its assembly difficult. Removing such deformations with mechanical or thermal procedures [6
] is often a time consuming task, which significantly impacts the final price of the welded structure. On the other hand, the residual stresses in the weld and the heat affected zone can promote crack initiation, especially in dynamically loaded structures.
Since the occurrence of residual stresses and deformations due to welding is an inevitable phenomena, it is necessary to know their distribution as accurately as possible in order to take adequate measures already at the design stage to reduce them. For this purpose, it is reasonable to apply numerical methods in order to avoid expensive experimental measurements [10
]. Regarding the above mentioned residual stresses and deformations caused by MAG welding, there are numerous numerical and experimental studies in the scientific literature for all important forms of welded structures, some of which are elaborated below.
Based on the experimental measurements, Adamczuk et al. [17
] presented a methodology for angular deformation predictions for multi pass butt-welded steel plates. Costa et al. [18
] investigated residual stresses numerically and experimentally and compared them using the X-ray procedure due to cold-wire and conventional MAG welding. In their work, Heinze et al. [19
] studied the influence of thermal material properties on the weld pool size and metallurgical properties of welded joints. Furthermore, Kung et al. [20
] numerically simulated and experimentally measured the influence of a welding jig position on the residual stresses and deformations for a multi pass butt-welded sample. Deng et al. [21
] took into account geometrical and material nonlinearities and investigated the influence of a weld reinforcement shape on the deformations in the MAG welded plates. In their work, Deng et al. [22
] numerically simulated and experimentally measured the deformations of middle-thick T-joint steel plates welded with the MAG procedure. Some possibilities of speeding-up numerical simulations with the application of a combination of shell and solid finite elements on a T-joint welded sample were suggested by Perić et al. [23
]. Furthermore, to additionally shorten the welding process simulation time, Perić et al. [24
] presented a simplified numerical T-joint model, where only the finite element reactivation or element birth/death technique was applied in the thermal numerical analysis, while the mechanical analysis was performed in one step. Prajadhiana et al. [25
] investigated T-joint welding deformations using virtual manufacturing tools and simplified numerical procedures.
Numerical simulations and experimental investigations of deformations and residual stresses are not only limited to the butt-welded and T-joint welded structures described above but are widely performed on large complex MAG welded panel structures that find widespread application in many industries. Deng et al. [26
] calculated the welding deformations on a large panel structure using the inherent strain method (ISM). The needed data for ISM calculations were obtained from a small-scale model where the full thermal-elastic-plastic (TEP) simulation procedure was applied. A similar approach was used by Azad et al. [27
], Zhang et al. [28
], Podder et al. [29
], and many other authors. On the other side, Perić et al. [30
] presented a simplified TEP procedure for the welding of residual stresses and deformation calculations in large structures. Here, heat input was applied by using the prescribed thermal boundary conditions instead of applying the heat flux to simulate the moving of the electrode in order to speed up the calculation process. Furthermore, Wu et al. [31
] and Zhao et al. [32
] investigated the residual stresses in MAG butt-welded pipes, while the residual stresses and deformations in MAG welded lap joints are studied by Lin et al. [33
It is worth noting that all of the above cited studies of residual stresses and deformations were performed on conventional MAG welded structures. One of the main disadvantages of the conventional MAG process is the relatively low deposit rate and depth of penetration, thus the welding of thicker structures requires a large amount of welding passes, which prolongs the product manufacturing process and increases financial costs. With the development of high current MAG technology (also known as buried-arc welding) [34
], the number of welding passes can be significantly reduced due to the increased deposit of molten metal. Unlike conventional MAG welded structures, where the residual stress and deformation fields and their magnitudes are well investigated, such studies in the scientific literature data regarding buried-arc welded structures are limited. In their previous studies, Perić et al. [35
] numerically and experimentally investigated temperature fields, residual stresses, and deformations on butt-weld and T-joint fillet weld samples. In this paper, the numerical and experimental investigations of temperature and residual stress distributions are further extended to circular patch welded structures often used in repair welding applications.