Evaluation by FEM of the Influence of the Preheating and Post-Heating Treatments on Residual Stresses in Welding

2014 ◽  
Vol 627 ◽  
pp. 93-96 ◽  
Author(s):  
Raffaele Sepe ◽  
Enrico Armentani ◽  
Giuseppe Lamanna ◽  
Francesco Caputo
Keyword(s):  
Temperature Distribution ◽  
Residual Stresses ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Element Model ◽  
Butt Joint ◽  
Temperature Fields ◽  
Heating Process ◽  
Butt Weld ◽  
Metal Arc Welding

During the last few years various experimental destructive and non-destructive methods were developed to evaluate residual stresses. However it is impossible to obtain a full residual stress distribution in welded structures by means of experimental methods. This disadvantage can be solved by means of computational analysis which allows to determine the whole stress and strain fields in complex structures. In this paper the temperature distribution and residual stresses were determined in a single-pass butt joint welded by GMAW (Gas Metal Arc Welding) process by finite element model (FEM). A 3D finite parametric element model has been carried out to analyze temperature distribution in butt weld joints and thermo-mechanical analyses were performed to evaluate resulting residual stresses. Temperature fields have been investigated by varying an initial preheating treatment. Moreover the technique of “element birth and death” was adopted to simulate the process of filler metal addition The high stresses were evaluated, with particular regard to fusion zone and heat affected zone. The influence of preheating and post-heating treatment on residual stresses was investigated. The residual stresses decrease when preheating temperature increases. The maximum value of longitudinal residual stresses without pre-heating can be reduced about 12% and 38% by using the preheating and post-heating process respectively.

scholarly journals Evaluation of Heat Sources for the Simulation of the Temperature Distribution in Gas Metal Arc Welded Joints

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1142 ◽  
Author(s):  
Andrea Chiocca ◽  
Francesco Frendo ◽  
Leonardo Bertini
Keyword(s):  
Temperature Distribution ◽  
Residual Stresses ◽  
Welded Joints ◽  
Initial Temperature ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Experimental Measurements ◽  
Thermal Methods ◽  
Simple Method ◽  
Metal Arc Welding

Residual stresses can affect both the static strength and the fatigue endurance of welded joints. Residual stresses can be assessed by numerical simulation; however, the simulation of the welding process is a complex task that requires knowledge of several parameters, many of which can only be estimated with some uncertainty. The reduction in the number of these parameters can lead to a more feasible and efficient study. In this work, the finite element method is used to assess the capability of different thermal methods used to simulate a single pass of the gas metal arc welding process in reproducing the temperature distribution around the weld. Results of the simulations are compared to experimental measurements of the surface temperature close to the welding area. The thermal techniques analyzed adopt different levels of complexity, from the basic implementation of a constant initial temperature assigned to a given material volume, to the more comprehensive and widespread Goldak’s double-ellipsoid model. The study shows that, close to the weld seam, very similar thermal behaviors can be achieved by employing each one of the analyzed methods. Secondly, considering the constant initial temperature method, the comparison between experimental measurements and numerical simulations showed a fairly good agreement, suggesting that a relatively simple method (i.e., requiring the setting of only one parameter) can be used to efficiently reproduce the thermal history of a welding process.

Distortion Prediction of Welded Thin Plate Lap Joints by Finite Element Analysis and Experiment

2019 ◽  
Vol 796 ◽  
pp. 175-182
Author(s):  
Mohamad Nizam Ayof ◽  
Ruzaini Mohd Nawi ◽  
Nur Izan Syahriah Hussein ◽  
Nor Zulaikha Zainol
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Gas Metal Arc Welding ◽  
Three Dimensional ◽  
Welding Process ◽  
Element Model ◽  
Lap Joints ◽  
Lap Joint ◽  
Element Analysis ◽  
Metal Arc Welding

Welding process is an efficient joining process of metals that is achieved by gas metal arc welding (GMAW) process. Localized heating during welding process can result in distortion of the welded plate. The estimation of magnitude and distribution of distortion are important to maintain the quality of products. Finite element method is implemented to investigate the distortions behavior of thin steel plate, cold rolled (SPCC) material in lap joint using GMAW process. A three-dimensional, two-step thermomechanical finite element model study was applied to analyze and evaluate distortion behavior in lap joint. The result of distortion from finite element analysis (FEA) was compared to experimental data to validate the accuracy of the method.

Distortion Analysis on Multipassed Butt Weld Using FEM and Experimental Study

2011 ◽  
Vol 311-313 ◽  
pp. 811-814
Author(s):  
Mohd Ridhwan Mohammed Redza ◽  
Yupiter H.P. Manurung ◽  
Robert Ngendang Ak. Lidam ◽  
Mohd Shahar Sulaiman ◽  
Mohammad Ridzwan Abdul Rahim ◽  
...  
Keyword(s):  
Gas Metal Arc Welding ◽  
Low Carbon Steel ◽  
Welding Process ◽  
Travel Speed ◽  
Source Model ◽  
Low Carbon ◽  
Robotic Welding ◽  
Butt Weld ◽  
Metal Arc Welding ◽  
Weld Distortion

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.

The Effect of Filler ER4043 and ER5356 on Porosity Distribution of Welded AA6061 Aluminum Alloy

2010 ◽  
Vol 146-147 ◽  
pp. 987-990
Author(s):  
Che Lah Nur Azida ◽  
Muhammad Faizol Ahmad Ibrahim ◽  
Azman Jalar ◽  
J. Sharif ◽  
Norinsan Kamil Othman ◽  
...  
Keyword(s):  
Welded Joints ◽  
Filler Metal ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Butt Joint ◽  
Hardness Profile ◽  
Porosity Formation ◽  
Metal Arc Welding ◽  
Arc Welding Process ◽  
Filler Metals

The filler metal used during welding process is believed to play an important role on porosity formation in aluminium alloy welded. The present investigation is aimed to study the effect of different fillers ER4043 (Al-5%Si) and ER5356 (Al-5%Mg) on porosity formation of AA6061 alloy welded joints. Butt-joint welds were made on 6 mm thick plates using 21 – 22 V arc voltages by using Gas Metal Arc Welding process (GMAW). The hardness profile of each types of AA6061 welded joints for both fillers were characterized by the Vickers microhardness test. In order to study the formation and distribution of porosity, the images of analysis were obtained using the X- ray CT-Scan. It was observed that, more porosities were found in the alloy AA6061 using ER4043 compared to ER5356 filler metals with the percentage area value of porosity about 18.3 and 8.4%, respectively. The hardness profile of ER5356 and ER4043 welded materials exhibited the similar hardness pattern profile. It is proposed that Si and Mg contents in the filler metal could play significant role in the distribution of porosity. No significant effect was observed on the hardness profile for both filler metals of welded materials.

scholarly journals Numerical and Experimental Validation of Gas Metal Arc Welding on AISI 441 Ferritic Stainless Steel Through Mechanical and Microstructural Analysis

2022 ◽  
Author(s):  
SERAFINO CARUSO ◽  
DOMENICO UMBRELLO
Keyword(s):  
Grain Size ◽  
Residual Stresses ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Microstructural Analysis ◽  
Welding Process ◽  
Production Costs ◽  
Metal Arc Welding ◽  
Residual Stresses And Strains ◽  
Welding Processes

Abstract Residual stresses and strains, distortion, heat affected zone (HAZ), grain size changes and hardness variation during gas metal arc welding (GMAW), are fundamental aspects to study and control during welding processes. For this reason, numerical simulations of the welding processes represent the more frequently used tool to better analyse the several aspects characterizing this joining process with the aim to reduce lead time and production costs. In the present study an uncoupled 3D thermo-mechanical analysis was carried out by two commercial finite element method (FEM) software to model an experimental single bead GMAW of AISI 441 at different process set-up. The experimental HAZ and measured temperatures were used to calibrate the heat source of both the used numerical codes, then a validation procedure was done to test the robustness of the two developed analytical procedures. One software was used to predict the residual stresses and strains and the distortions of the welded components, while in the second software a user routine was implemented, including a physical based model and the Hall-Petch (H-P) equation, to predict grain size change and hardness evolution respectively. The results demonstrate that the predicted mechanical and microstructural aspects agree with those experimentally found showing the reliability of the two codes in predicting the thermal phenomena characterizing the HAZ during the analysed welding process.

The Nonlinear Time-Varying Response of Dynamic Thermal Tensioning for Welding-Induced Distortion Control

2006 ◽  
Vol 129 (2) ◽  
pp. 333-341 ◽  
Author(s):  
Jun Xu ◽  
Wei Li
Keyword(s):  
Control Algorithm ◽  
Gas Metal Arc Welding ◽  
Superposition Principle ◽  
Welding Process ◽  
Structural Response ◽  
Element Model ◽  
Time Varying ◽  
Metal Arc Welding ◽  
Distortion Control ◽  
Thermal Tensioning

This paper presents a dynamic thermal tensioning method to control the welding induced distortion under production variation. The new method determines the optimal thermal tensioning parameters based on real-time distortion measurements. The paper is focused on a systematic study on the structural response and the development of an automatic control algorithm for the dynamic thermal tensioning process. A thermomechanical finite element model was used to study preheating effects in a gas metal arc welding process. A model predictive strategy was adopted for automatic distortion control. It has been found that the response of the dynamic thermal tensioning process is nonlinear and time varying. However, the response model can be linearized based on the superposition principle. A threshold-based control algorithm is developed and demonstrated using both simulation and experimental results.

Effects of stress concentration on the fatigue strength of 7003-T5 aluminum alloy butt joints with weld reinforcement

2015 ◽  
Vol 29 (10n11) ◽  
pp. 1540023 ◽  
Author(s):  
Zongtao Zhu ◽  
Yuanxing Li ◽  
Mingyue Zhang ◽  
Chen Hui
Keyword(s):  
Fatigue Strength ◽  
Stress Concentration ◽  
Fatigue Testing ◽  
Gas Metal Arc Welding ◽  
Cyclic Stress ◽  
Butt Joint ◽  
Al Alloy ◽  
Butt Joints ◽  
Butt Weld ◽  
Metal Arc Welding

7003-T5 Aluminum ( Al ) alloy plates with a thickness of 5 mm are welded by gas metal arc welding (GMAW) method in this work. In order to investigate the influence of stress concentration introduced by weld reinforcement on fatigue strength, the stress concentration factor of the butt joint is calculated. Microscopic and X-ray techniques were utilized to make sure there are no weld defects with large size in butt weld, which can induce extra stress concentration. The cyclic stress – number of cycles to failure (S–N) curves of the joints with and without the welder were obtained by fatigue testing, and the results show that the fatigue strength of 7003-T5 Al alloy butt joints with the weld reinforcement is 50 MPa, which is only 45% of the joints without the weld reinforcement. Fracture surface observation indicated that the fatigue source and propagation are dissimilar for the specimens with and without the welder due to the stress concentration at the weld root. The stress concentration with a factor of 1.7 has great effect on the fatigue strength, but little influence on the tensile strength.

scholarly journals Finite Element Modeling and Visualization of Additive Ring Growing by 3DMP Method

2020 ◽  
pp. short40-1-short40-8
Author(s):  
Andrey Kirichek ◽  
Sergey Barinov ◽  
Svetlana Fedonina
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Visual Information ◽  
Gas Metal Arc Welding ◽  
Heat Removal ◽  
Element Model ◽  
Temperature Fields ◽  
Technological Parameters ◽  
Metal Arc Welding ◽  
Hazardous Area

The aim of the work is to obtain a finite element model of the additive growing process in the general case of a complex-shaped product using the 3DMP (3D Metal Print) method of wire deposition / surfacing by gas metal arc welding, visualization of the forming temperature fields. The problem is solved using the example of an elementary ring by creating a scalable model in the Ansys software package. The stages of creating a finite element model as well as the results of its approbation in the analysis of temperatures are given. The model visualizes the nature of the influence of the deposition / surfacing parameters on the temperature fields that are formed and dynamically change with the movement of the wire feedstock. In this case, the conditions of additive free shaping of a closed-form product are of no small importance. It becomes possible to visually assess the degree of heating and the volume of heated metal in the hazardous area, proceed further to the calculation of stress and strain fields in the grown product, and choose the correct technological parameters of the process. The obtained visual information makes it possible to perform a qualitative and quantitative assessment of the additive shaping result, to determine the required intensity of heat removal, which contributes to the grown product quality improvement as a whole.

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