FE Simulation of Residual Welding Stresses: Aluminium and Steel Structural Components

Abstract

One of the decisive criteria in the selection of material between steel and aluminium could be the welding RS (residual stresses), which play an important role for the fatigue behavior of the structures under cycling loading. In the current paper simulations in commercial FE software ANSYS were carried out, in order to calculate the welding RS field for three different materials: structural steel S355 and the aluminum grades EN AW-6060 and EN AW-5754. In the case of EN AW-6060 influence of recrystallization on the yield strength of the HAZ (heat affected zone) was taken into consideration.

02.02: FE welding residual stress simulation: Influence of boundary conditions and material models

“…The method is also applicable to other materials. When austenitic steels or aluminium components are simulated the microstructural influence can be either neglected [11] or properly modified [12].…”

Reviewing the Influence of Welding Setup on FE-Simulated Welding Residual Stresses

“…The importance or negligibility of microstructural changes during modelling of ferritic or austenitic steels respectively has been confirmed in the past [2], [9]. Softening in the HAZ of aluminum alloys was as well successfully modelled elsewhere [8]. Nevertheless, a quantification of this influence on WRS is not known to the authors of the present study.…”

“…welding simulation, TRIP stands for transformed induced plasticity [2] Regarding the modelling of the microstructural changes that take place, different models have been proposed in the past. A straightforward engineering approach, which was proposed by the authors of the present study [2], provided results with sufficient preciseness and can be applied for the simulation of various materials [8], [9], [10]. Main feature of the approach lies on the assignment of material models to the finite elements inside the fusion zone (FZ) and the heataffected zone (HAZ) during cooling down based on predominant parameters of the thermal cycle, in order to simulate the modified mechanical behavior of the transformed microstructure.…”

“…The results are reviewed from a different scope in the present study in order to estimate the possible error of calculated WRS under the assumption that an under-or overestimation of ± 10 % of the weld heat source's efficiency has taken place. • Microstructural modelling: Numerical studies regarding welding of Aluminum alloy initially presented at [8], are repeated in the present study, by neglecting this time the phase transformations, in order to evaluate qualitatively and quantitatively the influence of recrystallization in the HAZ of aluminum alloys on the simulated WRS. A single-pass V grooved component of EN AW-6060 welded with an electric power of 3.1 kW and a welding speed of 10 mm/s (60 cm/min; 0.31 kJ/mm heat input) is modelled.…”

04.16: Rethinking imperfections in tanks and silos

“…On the basis of the above descriptions of their origins, radial imperfections should be irregular. However, each fabrication process should produce characteristic imperfection patterns: multi-layer or single layer welds; TIG welded on very thin stainless steel tanks or submerged arc welds on thicker structural steel tanks; aluminium silos or steel silos [36]; welded or bolted construction.…”