Response surface based model updating of TIG welded structure of hollow structural section (HSS) column

Abstract

Tungsten inert gas (TIG) welding is an electrical arc welding method that commonly used in the fabrication of engineering structure to join either ferrous or nonferrous metals due to great control over weld area comparing to other welding methods such as metal inert gas (MIG). A limited study can be found on finite element (FE) modelling technique of a structure that jointed by TIG welding method especially with a concerning of the dynamic analysis. This paper presents a systematic scheme to model the TIG weld of the welded structure in order to mimic experimental result of the TIG welded structure accurately using FE method. The welded joint of the FE model is developed by employing the area contact model (ACM2) format element connector. In order to evaluate the accuracy of the developed FE model, the predicted dynamic behaviour is compared with the experimental counterpart. The combination of impact hammer, roving accelerometers and free boundary conditions techniques are implemented in obtaining reliable experimental data for correlation analysis. For improving the accuracy of predicted model of the welded structure in light of experimental, FE model updating is utilised by coupled the response surface method with sensitivity analysis with minimisation of natural frequencies as objective function. The results obtained proved the capabilities of ACM2 model to represent as TIG welded joint. However, the requirement to identify updating parameters using sensitivity analysis for improving the predicted model is paramount importance.