Residual Stress Pattern Prediction in Spray Transfer Multipass Welding by Means of Numerical Simulation

Abstract

One of the main problems of gas metal arc welding (GMAW) process is the generation of residual stresses (RS), which has a direct impact on the mechanical performance of welded components. Nevertheless, RS pattern prediction is complex and requires the simulation of the welding process. Consequently, most of the currently used dimensioning approaches do not consider RS, leading to design oversized structures. This fact is especially relevant in big structures since it generates high material, manufacturing and product transportation costs. Nowadays, there are different numerical methods to predict the RS generated in GMAW process, being Goldak's method one of the most widely used model. However, the use of these methods during the design process is limited, as they require experimentally defining many parameters. Alternatively, in this chapter, a new methodology to define the heat source energy based on the spray welding physics is exposed. The experimental validation of the methodology conducted for a multipass butt weld case shows good agreement in both the temperature pattern (9.16% deviation) and the RS pattern (42 MPa deviation). Finally, the proposed methodology is extended to analyse the influence of the thickness and the number of passes in the RS pattern of thick T-joint welds.

Fatigue assessment of welded joints and crack growth considering residual stress

“…Figure 3 shows the heat distribution determined in this study using FEM. Comparing against FE and experiment results of Esnaola et al [32], it can concluded that distribution and the maximum heat determined in the current study are close to FE result of Esnaola et al [32].…”

“…In the present study, the coupled (two-way) method is employed for residual stress analysis of welding, and heat source is modelled as body flux on each weld component. To evaluate the accuracy of FEA for residual stress analysis a butt weld of Gas metal arc welding (GMAW) between two plates with dimensions of 200 × 10 mm is taken from the research work of Esnaola et al [32], which is shown in figure 1.…”

“…Esnaola et al [32] determined heat distribution using thermocouple and thermographic camera and the result compared with FEM. Figure 3 shows the heat distribution determined in this study using FEM.…”

“…Neto et al [31] studied numerically the effect of residual stress on fatigue crack growth. Esnaola et al [32] determined temperature and residual stress distribution in a multi pass butt weld using new method to define heat source energy.…”

A numerical analysis of multiaxial fatigue in a butt weld specimen considering residual stresses

“…Then, according to the welding speed and material addition discretization size, elements are reactivated (rebirthed) simulating the welding torch pass (Fig. 2) [15].…”