Multi-Objective Optimization of Bead Geometry for Submerged Arc Welding of Pipeline Steel Using RSM-Fuzzy Approach

2016 ◽  
Vol 16 (3) ◽  
pp. 141-151 ◽  
Author(s):  
Satish Kumar Sharma ◽  
Sachin Maheshwari ◽  
Sandeep Rathee

AbstractIn this paper, for the purpose of better control as well as multi-objective optimization of bead geometry parameters, the optimal combination of submerged arc welding (SAW) process variables is determined using fuzzy logic approach. Open circuit voltage, trolley speed, contact tube to work distance, preheating temperature and wire feed rate are taken as process variables during SAW of the pipeline steel. For this experimental investigation, experiments are designed and performed according to response surface methodology (RSM). Bead width, penetration, and reinforcement are taken as the performance measures in bead geometry. In fuzzy logic, two membership function (MF) namely triangular and trapezoidal are employed for the performance comparison of SAW process. As compared to triangular MF, the use of trapezoidal MF has given the more logical and better-optimized results for bead geometry parameters. Outcomes of the study are also confirmed by conducting the confirmatory experiments.

2016 ◽  
Vol 16 (4) ◽  
pp. 263-271 ◽  
Author(s):  
Satish Kumar Sharma ◽  
Sachin Maheshwari

AbstractIn any type of welding, its heat affected zone (HAZ) is the most critical section where the probability of hydrogen or solidification cracking is prominent. Continuous efforts are being applied by researchers and welders to minimize HAZ and its alterations. For the same purpose, by varying the factors of submerged arc welding (SAW) process which directly influences the heat input and cooling rate of the weld, experiments are carried out on the plates of micro-alloyed high strength pipeline steel. Voltage, welding speed, contact tube to work distance, wire feed rate and preheating temperature are taken as process variables. The experiments are designed according to the central composite rotatable design approach of response surface methodology (RSM). Multi-objective optimization of HAZ characteristics (HAZ area and its hardness) is carried out using grey relational analysis (GRA). To un-correlate the correlated characteristics of HAZ, principal component analysis (PCA) approach is coupled with GRA. The results of the confirmatory test have shown an improvement of 28.51 % and 5.94 % in area and hardness value of HAZ respectively at optimal setting combination of SAW process parameters.


Author(s):  
Navid Ansaripour ◽  
Ali Heidari ◽  
Seyed Ali Eftekhari

Residual stresses and distortion in welded joints undermine the durability of the structure and prevent a correct assembly of the parts. The principal objective of this study is to find a solution to minimize the residual stresses and distortion induced by submerged arc welding process. Accordingly, first, a thermal simulation of the process was undertaken by the finite-element method, and the results were used to provide a mechanical solution. The mechanical solution determined residual stresses and distortion that were found to be consistent with experimental results. Next, drawing on the design of experiment method based on cooling time between first pass and second pass and the first and second pass welding speed, a set of training data was formed for the developed artificial neural network. The trained neural network was then used as input for the optimization algorithm. Single- and multi-objective Genetic Algorithm and single and multi-objective Harmony Search methods were used for optimization process. Results illustrate that artificial neural network and multi-objective optimization algorithms are excellent methods for optimizing the residual stresses and distortion caused by welding process. As it was proved in this study, the single-objective optimization of the welding process is effective in reducing both the residual stress and distortion. The double-objective optimization also contributed to reduce both residual stress and distortion with 4% (for residual stresses) and 26.56% (for distortion) in multi-objective Harmony Search which was the better algorithm based on the solution time. Given the contradiction of the residual stresses and distortion in the welding process, the double-objective algorithm was found to be less successful in minimizing the two target functions relative to the case with the two optimized separately.


2012 ◽  
Vol 622-623 ◽  
pp. 45-50 ◽  
Author(s):  
Joydeep Roy ◽  
Bishop D. Barma ◽  
J. Deb Barma ◽  
S.C. Saha

In submerged arc welding (SAW), weld quality is greatly affected by the weld parameters such as welding current, traverse speed, arc voltage and stickout since they are closely related to weld joint. The joint quality can be defined in terms of properties such as weld bead geometry and mechanical properties. There are several control parameters which directly or indirectly affect the response parameters. In the present study, an attempt has been made to search an optimal parametric combination, capable of producing desired high quality joint in submerged arc weldment by Taguchi method coupled with weighted principal component analysis. In the present investigation three process variables viz. Wire feed rate (Wf), stick out (So) and traverse speed (Tr) have been considered and the response parameters are hardness, tensile strength (Ts), toughness (IS).


Author(s):  
P Biswas ◽  
N R Mandal

Determination of distortions are important while designing the arc-welded joints. These distortions occur in a varied way in almost every type of welded joint, depending on several parameters, i.e. welding speed, plate thickness, welding current and voltage, restraints applied to the job while welding, thermal history, etc. In the present work a numerical model based on the finite element package ANSYS was developed for single-pass single-sided submerged arc welding of square butt joints. Suitable macros were developed to simulate the situation of a moving distributed heat source, metal deposition to account for top and bottom reinforcements, a time step, and a meshing scheme. In this model the effect of bead geometry was incorporated. The effect of filler metal deposition was taken into account by implementing the element birth and death technique. Submerged arc welding (SAW) can be conveniently used to weld a range of plate thicknesses in a single run using a suitable backing strip achieving adequate top and bottom reinforcements. The welding methodology established in the present work resulted in minimizing angular distortions in butt welds. The numerical model yielded results comparing well with those of the experimental ones.


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