Ghalib Tham

Prediction of Welding Parameters and Weld Bead Geometry for GMAW Process in Overhead T-Fillet Welding Position (4F)

The prediction of welding parameters and weld bead geometry for GMAW process in Overhead T-fillet welding position (4F) is presented in this paper. This welding position is applied in construction of steel structures and ship building. The task to discover the range of welding parameter that can deposit quality fillet weld in overhead position is difficult, and the cost of developing them by trial and error is high. Robotic GMAW welder is employed to weld in 4F position with CO2 shielding. The current, voltage and speed as parameters, wire extension at 13mm constant. Only weld coupons are analyzed by macro-etching and the fillet geometry is plotted graphically to display the correlation with the respective welding parameter, particularly the heat input. Trend-lines with mathematical formulas are selected to develop the fillet geometry predictor. The predicted fillet geometry is validated by comparing with the values from actual welded coupons. The mean absolute deviation (MAD) of the predicting calculator is less than 1.0mm, it is therefore accurate and valid for industrial application.

Optimizing Robotic Welding Parameter of Single Passed Butt Joint under Simultaneous Consideration of Multiple Response Using Multi Objective Taguchi Method

This paper presents an alternative method to optimize parameters on single V butt welding. The effect of single-passed welding parameters such as current, voltage, welding speed and width of weaving movement on major welding defects by using a one-sided clamping method was investigated. The optimum parameter values were analyzed using Multi Objective Taguchi Methods (MTM) which started with the application of the common Taguchi methods (L8) Orthogonal Array (OA) and Total Normalized Quality Loss (TNQL) followed by ANOVA under simultaneous consideration of response weighting factors. Further, the value was analyzed by employing Multi Signal to Noise Ratio (MSNR). For the experimental study, a robotic welding system ABB IRB 2400/16 with digital welding power source KEMPPI Pro Evolution ProMIG 540 MXE with shielding gas Argon 80% and Carbon Dioxide 20% were applied. The material used is low carbon steel with 4 mm plate thickness. Based on the verification test result, it is found out that MTM can be used as an alternative method to investigate the optimum value of single passed welding parameter with multiple quality features.

Modeling and optimization of weld zone development in resistance seam welding

Resistance Seam Welding (RSEW) is an ideal welding method to produce airtight joints where welding input parameters play a very significant role in determining the quality of weld nugget and heat affected zone (HAZ) formation. This research is aimed to study the nugget and HAZ development of 1 mm low carbon steel using RSEW. Welding parameters such as weld current, weld time, weld speed and pressure were identified and investigated to study their effect on the formation of weld nugget by using 24 factorial designs. The objective of this work is to find the optimum parameter to optimize the width of weld nugget and HAZ in order to obtain a good quality of RSEW. Furthermore the mathematical models were developed to predict the weld zone development. Experimental confirmation test was conducted at an optimal condition for observing accuracy of the developed model. Based on the confirmation test, the proposed method can be effectively used to predict the size of weld zone which can improve the welding quality and performance in RSEW.

Transversed Residual Stress Analysis on Multipassed Fillet Weld 2D-Using FEM and Experiment

In this project, the residual stress due to multipassed welding process at the fillet weld will be studied using 2D Finite Element Analysis (FEA) simulation method and experimental investigation. Due to the extensive capabilities and dedicated tools for the simulation of welding, including material deposit via element activation or deactivation and predefined or customized moving heat sources, SYSWELD 2010 was chosen as the FEA software. The material with a thickness of 9 mm was structural steel S355J2G3 for simulation and low carbon steel for the experiment. The clamping condition was selected to obtain the best relationship between simulation and experiment by using Strain Gage. The model was dedicated to multipassed welding using the robotic welding system

Distortion Analysis on Multipassed Butt Weld Using FEM and Experimental Study

This paper investigates the simulation technique for analyzing the distortion behavior induced by welding process on welded plate which was clamped on one side. This clamping method is intended to enable the investigation of the maximum distortion on the other side. FEA software SYSWELD was employed to predict multipassed butt weld distortion of low carbon steel with thicknesses of 6 mm and 9 mm. The simulation begins with the development of model geometry and meshing type followed by suitable selection of heat source model represented by the Goldak’s double ellipsoid model. Other parameters such as travel speed, heat input, clamping method etc. were determined. The model is dedicated for multipass welding techniques using Gas Metal Arc Welding (GMAW). The experimental works were conducted by using Robotic welding process.