Finite Element Simulative Analysis on the Influence of Solid-State Transformation on Welding Residual Stress

2013 ◽  
Vol 785-786 ◽  
pp. 1229-1235 ◽  
Author(s):  
Chun Run Li ◽  
Zhi Peng Zhang ◽  
Yi Ming Zhang ◽  
Zong Tao Fang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Solid State ◽  
Phase Change ◽  
Weld Zone ◽  
Thermal Strain ◽  
Welding Process ◽  
Welding Residual Stress ◽  
State Transformation ◽  
Solid State Transformation

This paper takes the Q345 steel as an example, adopting finite element simulative analysis to study the influence of solid-state transformation on welding residual stress. By setting the value of the thermal strain in different temperature, the change in volume caused by the phase changes is equivalent to the thermal strain. Simulation includes two cases which are consideration of phase transformations and not consideration. The results showed that the distribution trend of the longitudinal stress of the weld zone is substantially the same in the two simulations. In the case of not consider the simulation of phase change, there is a lot of stress in the weld zone and the heat affected zone and the maximum value could be 427 MPa. In regard to transverse stress, phase change not only affects the value of the stress, but also changes the direction of the stress of the weld middle portion. Welding residual stress is also measured by X-ray. Phase change simulation and experimental results are in good agreement, it can be concluded that phase change in the welding process will result in a significant impact on the distribution of the residual stress, which could not be ignored in the finite element simulation of welding process.

Analysis on the Welding Thermal Field and Residual Stress of Thick Plate

2015 ◽  
Vol 1095 ◽  
pp. 693-697
Author(s):  
Jiu Hong Jiang ◽  
Qiang Wang ◽  
Wen Lv
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Thick Plate ◽  
Thermal Field ◽  
Welding Process ◽  
Source Model ◽  
Simulation Software ◽  
Welding Residual Stress ◽  
Element Simulation ◽  
Thick Steel

A 60mm Q345 rigid thick plate with V groove welding connection was modeled in order to simulate the welding residual stress by finite element method. Both element birth and death technique and double ellipse heat source model were introduced to simulate the welding process. The welding thermal field and residual stress of thick steel plate were analyzed by finite element simulation software ANSYS.Then the thermal field and residual stress distribution were visually demonstrated. The result shows that the thermal field shaped like a spindle during welding period and the residual stress at the mid-section in lateral, longitudinal and thickness direction of the welding joint is lower than the stress at the surface of the welding connection.

Simulation of Welding Residual Stress to the Fracture Strength of Steel Moment-Resist Frame Connection

2011 ◽  
Vol 250-253 ◽  
pp. 3682-3687
Author(s):  
Te Wei Fan
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Fracture Strength ◽  
Brittle Failure ◽  
Weld Zone ◽  
Welding Residual Stress ◽  
Failure Behavior ◽  
Element Analysis ◽  
Fracture Models

Inspection made for moment-resist frame connection assembled by welding found that most failures occurred in weld zone between beam and column flange connections, and these failures were caused by cracks initiated at the root of weld. The main reason for the crack initiation is not plastic deformation as expected, and the evaluation results indicated that the major failure mechanism for the brittle failure behavior of moment-resist frame (MRF) connection is caused by the residual stress induced by welding. This paper use finite element method to simulate welding residual stress, and apply them into 3D fracture models. With fracture parameters calculated in finite element analysis, information about fracture strength of MRF connection is acquired.

scholarly journals Estimation formula for residual stress from the blind-hole drilling method

2018 ◽  
Vol 10 (8) ◽  
pp. 168781401878740 ◽  
Author(s):  
Chi-Liang Kung ◽  
Ah-Der Lin ◽  
Po-Wei Huang ◽  
Chao-Ming Hsu
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Welding Process ◽  
Welding Residual Stress ◽  
Hole Drilling ◽  
Parameter Group ◽  
Blind Hole ◽  
Finite Element Software ◽  
Inconel 690 ◽  
Stress Components

In this study, the accuracy of blind-hole method on weld residual stress estimation is investigated. A modified parameter group has also proposed to improve the accuracy. The thermal-elastic-plastic finite element model is employed to build up the residual stress distribution and the blind-hole process. The MSC Marc finite element software package is used to simulate the welding process and the welding residual stress and strain distributions around the weld of two inconel 690 alloy plates filled with I-52 GTAW filler. Then the process of the traditional blind hole is simulated by employing the inactive elements. The data of the residual strain variations of strain gages located around the blind hole is introduced into the blind-hole method to estimate the original residual stress components at the hole center. The effects of drilling depth, drilling size, gage radius, gage position, and the distance on the accuracy of estimated residual stress have also been studied and discussed. Based on the residual stress components simulated from the welding process, a modified stress parameter group has also been proposed to improve the accuracy of blind-hole method. Numerical results indicate that the accuracy of estimated residual stress can be improved significantly by employing the proposed blind-hole parameters.

scholarly journals Finite Element Prediction of Residual Stress Distributions in a Multipass Welded Piping Branch Junction

2006 ◽  
Author(s):  
Wei Jiang ◽  
Kadda Yahiaoui
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Welding Process ◽  
Pressure Vessels ◽  
Welding Residual Stress ◽  
Stress Distributions ◽  
Multipass Welding ◽  
Hexahedral Elements ◽  
Element Removal

Piping branch junctions and nozzle attachments to main pressure vessels are common engineering components used in the power, oil and gas, and shipbuilding industries amongst others. These components are usually fabricated by multipass welding. The latter process is known to induce residual stresses at the fabrication stage which can have severe adverse effects on the in-service behavior of such critical components. It is thus desirable if the distributions of residual stresses can be predicted well in advance of welding execution. This paper presents a comprehensive study of three dimensional residual stress distributions in a stainless steel tee branch junction during a multipass welding process. A full 3D thermo-mechanical finite element model has been developed for this purpose. A newly developed meshing technique has been used to model the complex intersection areas of the welded junction with all hexahedral elements. Element removal/reactivate technique has been employed to simulate the deposition of filler material. Material, geometry and boundary nonlinearities associated with welding were all taken into account. The analysis results are presented in the form of stress distributions circumferentially along the weldline on both run and branch pipes as well as at the run and branch cross sections. In general, this computational model is capable of predicting 3D through thickness welding residual stress, which can be valuable for structural integrity assessments of complex welded geometries.

Structure Optimization and Welding Residual Stress Analysis of Twin-Web Turbine Disc

2012 ◽  
Vol 622-623 ◽  
pp. 309-314 ◽  
Author(s):  
Xiu Li Shen ◽  
Shao Jing Dong
Keyword(s):  
Residual Stress ◽  
Weight Loss ◽  
Finite Element ◽  
Numerical Calculation ◽  
Stress Analysis ◽  
Welding Process ◽  
Structure Optimization ◽  
Welding Residual Stress ◽  
Turbine Disc ◽  
Residual Stress Analysis

This paper has proposed a new shape of the twin-web turbine disc. Based on a design optimization of the shape of the twin-web turbine disc by finite element numerical calculation, we analyzed welding types and carried out the simulation of the welding process and obtained the residual stress. Finally we got a 5.8% weight loss and summarized residual stress of the welding and proved the feasibility of the new shape.

Influence Analysis of Welding Residual Stress for Seismic Behavior to Side-Plate Reinforced Section

2012 ◽  
Vol 256-259 ◽  
pp. 2074-2078
Author(s):  
Yun Liu ◽  
Cheng Chao Mao ◽  
Yong Jie Song ◽  
Xue Jing Song
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Seismic Behavior ◽  
Welding Process ◽  
Welding Residual Stress ◽  
Finite Element Models ◽  
Side Plate ◽  
Research Objects ◽  
Seismic Index ◽  
Element Method

Taking side-plate reinforced section as research objects, this paper establishes the models by Ansys non-linear finite element method and simulates welding process of with birth-death element method. Comparing the different seismic index among test specimen and finite element models that based on whether or not considering welding residual stress, based on which, this research draws a conclusion that the influence of welding residual stress for seismic behavior to side-plate reinforced section is not obvious.

Numerical Simulation of Welding Residual Stress Considering Phase Transformation Effects

2011 ◽  
Vol 295-297 ◽  
pp. 1905-1910 ◽  
Author(s):  
Hai Zhang ◽  
Dong Po Wang ◽  
Sen Li
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Phase Transformation ◽  
Volume Change ◽  
Weld Zone ◽  
Thermal Strain ◽  
Welding Residual Stress ◽  
Different Temperatures ◽  
History Of ◽  
Welding Processes

The welding processes of steel materials are often accompanied by the occurrence of phase transformation. Volume change caused by phase transformation will affect the history of stress and strain. In this article, taking the welding of Q345 as an example, the effects of solid-state phase transformation on the residual stress were investigated by numerical simulation. The values of thermal strain at different temperatures were set to make the volume change caused by phase transformation equivalent as thermal strain. The simulation contained two cases both considering phase transformation and not. The results show that in both two cases the longitudinal stress distribution in the weld zone has almost the same trend. But in the case without considering phase transformation, there is large longitudinal tensile stress concentrating in the weld and HAZ zone and the maximum value is up to 427MPa in the weld. For transverse stress, phase transformation not only changes the value of the stress, but also alters the sign of the stress in the middle of the weld zone. Experiment was also carried out to measure the residual stress by X-ray diffraction. The result considering phase transformation matched much better with the experimental data. It can be concluded that phase transformation in the process of welding has a significant effect on the residual stress and can not be ignored in the numerical simulation of welding.

Finite Element Analysis Model and Residual Stress Optimization in Rotor Welding Process

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Zhufeng Liu ◽  
Yonghui Xie ◽  
Hao Dang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Distribution ◽  
Thermal Strain ◽  
Welding Process ◽  
Optimization Method ◽  
Mechanical Analysis ◽  
Analysis Model ◽  
Element Analysis ◽  
Stress Optimization

Abstract In this paper, the finite element method (FEM) is conducted for thermal and mechanical analysis of a half 2D axisymmetric welded rotor model. The temperature results after welding are obtained and supported by the experiment results. Furthermore, the thermal strain and residual stress of the weld are analyzed in detail by considering solid-state phase transformation (SSPT). Besides, parametric optimization method is adopted to optimize the region of large stress distribution. By choosing the weld pass number as the optimized parameter, the area decreases by 5.4% when the optimal pass number is 18. The axial and hoop stress distributions are obtained at the inner and outer surfaces near the weld for the better stress distribution.

Numerical Investigation on Heat Transfer and Residual Stress in a Butt Welded Plate

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
D. Kumaresan ◽  
A. K. Asraff ◽  
R. Muthukumar
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Thermal History ◽  
Plastic Material ◽  
Welding Process ◽  
Welding Residual Stress ◽  
Source Distribution ◽  
Geometrical Shape ◽  
Element Analysis ◽  
Alloy Plate

It is a well known fact that during welding, the metal at the welding zone gets melted and then solidifies, which results in shrinkage in all directions. Residual strain and stress distributions coming from shrinking are largely influenced by the nature and configuration of the welding process, metallurgical characteristics of weld, and the geometrical shape of the weld joint. The residual stress mainly depends on the thermal history cycle through which the specimen undergoes in the welding process. So these thermal history cycles are to be known in order to get a better knowledge of the welding phenomenon and to minimize the risk of failures. In this work, a detailed analysis has been carried out for predicting the heat flow pattern and stress distribution in an aluminum alloy plate during welding. In this study, the modified double ellipsoidal heat source distribution pattern is modeled and considered for the weld pool design. Elastic-plastic material properties at various temperatures are also considered for simulation. A detailed finite element analysis is carried out to predict the welding residual stress. In this, thermal analysis is carried out for actual variable welding speed and these transient thermal histories at various locations were numerically predicted and compared with experimental results. Further, these thermal results are used to predict the residual stress on the weld plate using finite element method.

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