Alternative simulation techniques for distortion of thin plate due to fillet-welded stiffeners

Abstract

This study aims to develop and validate a wide-ranging simulation tool to predict welding distortion in stiffened plates and shells, with particular emphasis on out-of-plane deformation. The approach adopted in this study uncouples the thermal, elasto-plastic and structural effects leading to distortion. The computational models and results are supported by realistic welding tests and appropriate measurements to validate the simulated thermal fields and out-of-plane distortions. The simplest and most computationally efficient model makes use of algorithms, instead of numerical computation, to link the thermal welding strains to the elasto-plastic and structural responses of the welded assembly, via a static, single-load-step analysis. Alternative, more computationally intensive models are explored which simulate the full transient thermal and elasto-plastic structural responses in an uncoupled fashion. These provide a cross-reference for the more rudimentary but computationally efficient models. The experiments and computational strategies are applied to welded assemblies incorporating double-fillet-welded stiffeners.

Simulating welding distortion in fillet welding of stiffened plate structures

“…Figure 11.2 shows that at points equidistant from the heat source on the plate, temperatures are similar, but the stiffener temperatures at corresponding distances are significantly higher. 1 This is confirmed by the thermographic study of Fig. 11.3, which shows higher temperatures over larger areas in the stiffener than in the base plate (see Fig.…”

Experimental investigation and finite element simulation of laser beam welding induced residual stresses and distortions in thin sheets of AA 6056-T4

“…The probable reason for this difference is the use of a constant heat transfer coefficient in air (h conv ). A literature survey [10,31,32] shows that the natural convective heat transfer coefficient is a function of temperature in some cases. Improvement in simulation results may, therefore, be expected by using a temperature dependent heat transfer coefficient.…”

“…Some research [6,7] has been dedicated entirely to thermal analysis and heat source modelling while other authors [8,9] have focussed upon welding induced stresses. With special reference to fillet-welded stiffeners, Camilleri et al [10,11] have suggested that the out-of-plane displacements can be efficiently predicted by computational means. Other workers [12,13] have predicted the residual stress state in friction stir welded panels and found that the collapse behaviour is less sensitive to advanced process effects than initial buckling of the panel.…”

Effect of shielding gas parameters on weld metal thermal properties in gas metal arc welding

“…Computational modelling has become increasingly popular over the past few decades for the prediction of various aspects of the welding process. Extensive studies have been conducted in areas fundamental to the final structure, namely residual stresses in the weld region [29,30,31], weld induced distortion [25,26,30,31] and the solidified weld geometry [10,31].…”

“…Mollicone et al [26] and Camilleri et al [31] presented dilatometer data, which indicated that the parent plate and filler material posses different coefficient of thermal expansions and, from this, it can therefore be inferred that the other thermal properties will also differ. Thus the accuracy of the simulation is only as accurate as the material property data supplied.…”