PSI - Issue 25

Romanin Luca et al. / Procedia Structural Integrity 25 (2020) 149–158 Author name / Structural Integrity Procedia 00 (2019) 000–000

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4. Conclusions A simplified numerical method aimed at predicting weld distortions on mega-structures is proposed. The method is based on the definition of virtual elements in which thermal gradients and pre-strains are applied to reproduce the deformation effect induced by welding. Such virtual loads are calculated for each simple welding geometry, according to materials and process parameters, by means of experiments or computational welding mechanics and inverse analysis. The effect of each welding on the assembly is then calculated by applying the superposition principle. The model was validated by using a real mega structure’s node built out of several welding runs. As predicted by the model, following the welding plan, the structure distortion in as-welding condition resulted acceptable. The direction of the deformation is predicted as well as its order of magnitude. The main drawback of the proposed approach is that it is unsensitive to welding sequence. A more general simplified method including non-linearity is going to be developed to overcome that issue. Deng, Dean, Hidekazu Murakawa, and Wei Liang. 2007. “Numerical Simulation of Welding Distortion in Large Structures.” Computer Methods in Applied Mechanics and Engineering 196(45–48): 4613–27. Ferro, P, H Porzner, A Tiziani, and F Bonollo. 2006. “The Influence of Phase Transformations on Residual Stresses Induced by the Welding Process-3D and 2D Numerical Models.” Modelling and Simulation in Materials Science and Engineering 14(2): 117–36. Ha, Yun Sok, and Geoje Shipyard. 2007. “An Improved Inherent Strain Analysis for Plate Bending by Line Heating Considering Phase Transformation of Steel.” 17(1): 1–6. Kim, Mingyu, Minseok Kang, and Hyun Chung. 2015. “Simplified Welding Distortion Analysis for Fillet Welding Using Composite Shell Elements.” International Journal of Naval Architecture and Ocean Engineering 7(3): 452–65. http://dx.doi.org/10.1515/ijnaoe-2015 0032. Lindgren, L.-E. (Lars-Erik). 2007. Computational Welding Mechanics : Thermomechanical and Microstructructural Simulations . CRC Press. Luca, Romanin, Ferro Paolo, and Berto Filippo. 2018. “ScienceDirect The Influence of Metallurgical Data on Residual Stresses in Computational Welding.” 00. Vega, Adan, Naoki Osawa, Sherif Rashed, and Hidekazu Murakawa. 2010. “Analysis and Prediction of Edge Effect on Inherent Deformation of Thick Plates Formed by Line Heating.” CMES - Computer Modeling in Engineering and Sciences 69(3): 261–79. Wang, Jiangchao, Sherif Rashed, Hidekazu Murakawa, and Yu Luo. 2013. “Numerical Prediction and Mitigation of Out-of-Plane Welding Distortion in Ship Panel Structure by Elastic FE Analysis.” Marine Structures 34: 135–55. http://dx.doi.org/10.1016/j.marstruc.2013.09.003. References