Finite element parametric study of the split sleeve cold expansion on residual stresses and pulling force

2021 ◽  
pp. 095440622110255
Author(s):  
Mithun K Dey ◽  
Dave Kim ◽  
Hua Tan
Keyword(s):  
Finite Element ◽  
Yield Strength ◽  
Residual Stresses ◽  
Parametric Study ◽  
Industrial Applications ◽  
Published Data ◽  
Fe Model ◽  
Residual Stress Field ◽  
Cold Expansion ◽  
Pulling Force

Split sleeve cold expansion (SSCE) is a crucial cost-effective process to improve the fatigue life of metallic structures with holes in the aerospace industry. In this study, the effects of the workpiece material’s yield strength (290.9 MPa to 377.8 MPa) and the applied SSCE expansion percentage (3.330% to 4.377%) on mandrel pulling force and residual stresses were investigated numerically for aluminum 2024-T351. A three-dimensional finite element (FE) model was developed to simulate the SSCE process using a commercial FE software, ABAQUS. The model geometries, material non-linearities, and contact conditions were adopted according to aerospace industrial applications’ standards. After the numerical model was validated with the published data, a parametric study with variable material properties and expansion percentage was conducted using the FE model. Our parametric study shows that an increase in both the Al workpiece’s yield strength and SSCE expansion percentage can improve the induced residual stresses in the hoop direction around the cold expanded hole; however, the workpiece’s yield strength has a higher impact on the residual stress field. The in-process pulling force during the SSCE process increases with increasing workpiece yield strength and expansion percentage.

Prediction of Residual Stress Distributions in Welded Sections of P92 Pipes with Small Diameter and Thick Wall based on 3D Finite Element Simulation

2015 ◽  
Vol 34 (3) ◽  
Author(s):  
Xiaowei Wang ◽  
Jianming Gong ◽  
Yanping Zhao ◽  
Yanfei Wang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Small Diameter ◽  
Fe Analysis ◽  
Thick Wall ◽  
Fe Model ◽  
Stress Distributions ◽  
Residual Stress Field ◽  
Heat Treated

AbstractThis study used ABAQUS finite element (FE) software to investigate the residual stress distributions of P92 welded pipes in both the as-weld and post weld heat treated (PWHT) condition. Sequential coupling quasi-static thermo-mechanical in conjunction with moving double ellipsoidal heat source and an element add/remove technique to simulate deposition of new weld material, are combined in the 3D FE analysis. To validate the simulation results, the residual stresses in axial direction at the surface of pipe were measured by X-ray diffraction technique and compared with the results of FE analysis. Detailed characteristic distributions of the residual stresses are discussed. Results show that the FE model can predict the residual stress distributions satisfactorily. Highest residual stresses on the outer surface are found in the last weld bead to be deposited. And the highest tensile residual stress for the full welded section take place in heat affected zone (HAZ) near the middle thickness. Larger residual sstress can be found around the welding start point along the pipe circumference. Comparison of heat treated specimen and untreated specimen illustrates that PWHT has a strong effect on the residual stress field.

Application of 3D Finite Element Modelling to Repair Weld Simulation in Industrial Applications

2002 ◽  
Author(s):  
George Vinas ◽  
Tamba Dauda ◽  
Nicola Moyes ◽  
Alan Laird
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Measurement Techniques ◽  
Fem Simulation ◽  
Welding Process ◽  
Industrial Applications ◽  
Welding Residual Stress ◽  
Experimental Techniques ◽  
Residual Stress Field

The Finite Element Method (FEM) has been implemented in 3D to predict welding residual stresses in repair welds. The analysis has been used to achieve more accurate residual stress predictions for the weld at the cost of long computation times. The use of this CPU intensive approach has been facilitated by the advent of ever-faster computer processors being made more accessible to the engineering community. The same technique has also been used with coarser meshes involving simplified welding sequences where a number of weld passes are “lumped” together to reduce the simulation time. The authors argue that this latter approach can be very useful in predicting the more global component response — in cases where 2D model symmetries are not applicable — and for rapid identification of problem areas where finer simulations would be prohibitive. The authors show an example of a residual stress prediction for a letterbox repair obtained using the FEM. Good agreement between this prediction and experimental measurements is shown. The FEM simulation technique has been used to predict residual stress formation during the welding process and subsequent service loading of the component. This analysis shows the residual stress field relaxation following “shakedown”. The component under service conditions is subjected to pressure loading and a small amount of bending stress. Based on recent residual stress experimental programmes conducted at Mitsui Babcock Energy Limited (MBEL), the authors provide a brief discussion on the ways in which various experimental techniques have been used to verify welding residual stress predictions from FE. The authors argue that just as there has been an interest in the field to measure residual stresses in the highly stressed regions of a weld, it is equally important to measure stresses in areas of relatively low stress to confirm that stresses do indeed die out away from welds. It is in the latter case where some experimental techniques cannot perform as well as other simple, well proven, strain measurement techniques.

scholarly journals Residual stresses in thermite welded rails: significance of additional forging

2020 ◽  
Vol 64 (7) ◽  
pp. 1195-1212
Author(s):  
B. Lennart Josefson ◽  
R. Bisschop ◽  
M. Messaadi ◽  
J. Hantusch
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Residual Stresses ◽  
Weld Metal ◽  
Welding Process ◽  
Surface Zone ◽  
Fe Model ◽  
Uneven Surface ◽  
Residual Stress Field ◽  
High Dynamic

Abstract The aluminothermic welding (ATW) process is the most commonly used welding process for welding rails (track) in the field. The large amount of weld metal added in the ATW process may result in a wide uneven surface zone on the rail head, which may, in rare cases, lead to irregularities in wear and plastic deformation due to high dynamic wheel-rail forces as wheels pass. The present paper studies the introduction of additional forging to the ATW process, intended to reduce the width of the zone affected by the heat input, while not creating a more detrimental residual stress field. Simulations using a novel thermo-mechanical FE model of the ATW process show that addition of a forging pressure leads to a somewhat smaller width of the zone affected by heat. This is also found in a metallurgical examination, showing that this zone (weld metal and heat-affected zone) is fully pearlitic. Only marginal differences are found in the residual stress field when additional forging is applied. In both cases, large tensile residual stresses are found in the rail web at the weld. Additional forging may increase the risk of hot cracking due to an increase in plastic strains within the welded area.

Stress and Fatigue Life Modeling of Cannon Breech Closures Including Effects of Material Strength and Residual Stress

2000 ◽  
Vol 123 (1) ◽  
pp. 150-154
Author(s):  
John H. Underwood ◽  
Michael J. Glennon
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Fatigue Life ◽  
Yield Strength ◽  
Residual Stresses ◽  
Solid Mechanics ◽  
Element Model ◽  
Pressure Vessels ◽  
Material Strength ◽  
Element Analysis

Laboratory fatigue life results are summarized from several test series of high-strength steel cannon breech closure assemblies pressurized by rapid application of hydraulic oil. The tests were performed to determine safe fatigue lives of high-pressure components at the breech end of the cannon and breech assembly. Careful reanalysis of the fatigue life tests provides data for stress and fatigue life models for breech components, over the following ranges of key parameters: 380–745 MPa cyclic internal pressure; 100–160 mm bore diameter cannon pressure vessels; 1040–1170 MPa yield strength A723 steel; no residual stress, shot peen residual stress, overload residual stress. Modeling of applied and residual stresses at the location of the fatigue failure site is performed by elastic-plastic finite element analysis using ABAQUS and by solid mechanics analysis. Shot peen and overload residual stresses are modeled by superposing typical or calculated residual stress distributions on the applied stresses. Overload residual stresses are obtained directly from the finite element model of the breech, with the breech overload applied to the model in the same way as with actual components. Modeling of the fatigue life of the components is based on the fatigue intensity factor concept of Underwood and Parker, a fracture mechanics description of life that accounts for residual stresses, material yield strength and initial defect size. The fatigue life model describes six test conditions in a stress versus life plot with an R2 correlation of 0.94, and shows significantly lower correlation when known variations in yield strength, stress concentration factor, or residual stress are not included in the model input, thus demonstrating the model sensitivity to these variables.

Evaluation of Residual Stresses in Butt Welded Joint of Dissimilar Material by FEM

2017 ◽  
Vol 754 ◽  
pp. 268-271 ◽  
Author(s):  
Raffaele Sepe ◽  
M. Laiso ◽  
A. de Luca ◽  
Francesco Caputo
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Arc Welding ◽  
Structural Integrity ◽  
Welded Joint ◽  
Dissimilar Material ◽  
Fe Model ◽  
Butt Joints ◽  
Integrity Assessment ◽  
Steel Joints

The study proposed within this paper deals with an application of finite element techniques to the thermo-structural analysis of a dissimilar butt-welded joint. Residual stresses induced by the fusion arc-welding of steel joints in power generation plants are a concern to the industry. Nowadays, the application of finite element method appears to be a very efficient method for the prediction and the investigation of the weld-induced residual stresses, nevertheless the detailed modelling of all phenomena involved in such process is still challenging. The structural integrity assessment of welded structures strongly requires a deep investigation of weld-induced residual stresses in order to be compliant with safety requirement of power plant. The longitudinal and transversal residual stresses in dissimilar material butt joints of 8 mm thick for V-groove shape were studied. The developed thermo-mechanical FE model as well as the simulation procedures are detailed and results are discussed. As a result of such work, it has been found out that residual stresses in the two dissimilar plates are characterized by very different magnitudes and distribution.

Finite Element Simulation of the Sachs Boring Method of Measuring Residual Stresses in Thick-Walled Cylinders

2003 ◽  
Vol 125 (3) ◽  
pp. 274-276 ◽  
Author(s):  
R. R. de Swardt
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Data Reduction ◽  
High Speed ◽  
High Strength ◽  
Residual Stress Field ◽  
Element Analysis ◽  
Element Mesh ◽  
Reduction Methods ◽  
Data Reduction Method

During a recent study the residual strain/stress states through the walls of autofrettaged thick-walled high-strength steel cylinders were measured with neutron diffraction, Sachs boring and the compliance methods (Venter et al., 2000, J. Strain Anal. Eng. Des., 35, pp. 459–469). The Sachs boring method was developed prior to the advent of high speed computers. A new method for the data reduction was proposed. In order to verify the proposed procedure, the Sachs boring experimental method was simulated using finite element modeling. A residual stress field was introduced in the finite element method by elasto-plastic finite element analysis. The physical process of material removal by means of boring was simulated by step-by-step removal of elements from the finite element mesh. Both the traditional and newly proposed data reduction methods were used to calculate the residual stresses. The new data reduction method compares favorably with the traditional method.

The Effects of Loadings on Welding Residual Stresses and Assessment of Fracture Parameters in a Welding Residual Stress Field

2011 ◽  
Author(s):  
Liwu Wei ◽  
Weijing He ◽  
Simon Smith
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Residual Stresses ◽  
Path Dependence ◽  
Welding Residual Stress ◽  
Assessment Procedure ◽  
Fe Model ◽  
J Integral ◽  
Residual Stress Field ◽  
Growing Crack

The level of welding residual stress is an important consideration in the ECA of a structure or component such as a pipeline girth weld. Such a consideration is further complicated by their variation under load and the complexity involved in the proper assessment of fracture mechanics parameters in a welding residual stress field. In this work, 2D axi-symmetric FEA models for simulation of welding residual stresses in pipe girth welds were first developed. The modelling method was validated using experimental measurements from a 19-pass girth weld. The modeling method was used on a 3-pass pipe girth weld to predict the residual stresses and variation under various static and fatigue loadings. The predicted relaxation in welding residual stress is compared to the solutions recommended in the defect assessment procedure BS 7910. Fully circumferential internal cracks of different sizes were introduced into the FE model of the three-pass girth weld. Two methods were used to introduce a crack. In one method the crack was introduced instantaneously and the other method introduced the crack progressively. Physically, the instantaneously introduced crack represents a crack originated from manufacturing or fabrication processes, while the progressively growing crack simulates a fatigue crack induced during service. The J-integral values for the various cracks in the welding residual stress field were assessed and compared. This analysis was conducted for a welding residual stress field as a result of a welding simulation rather than for a residual stress field due to a prescribed temperature distribution as considered by the majority of previous investigations. The validation with the 19-pass welded pipe demonstrated that the welding residual stress in a pipe girth weld can be predicted reasonably well. The relaxation and redistribution of welding residual stresses in the three-pass weld were found to be significantly affected by the magnitude of applied loads and the strain hardening models. The number of cycles in fatigue loading was shown to have little effect on relaxation of residual stresses, but the range and maximum load together governed the relaxation effect. A significant reduction in residual stresses was induced after first cycle but subsequent cycles had no marked effect. The method of introducing a crack in a FE model, progressively or instantaneously, has a significant effect on J-integral, with a lower value of J obtained for a progressively growing crack. The path-dependence of the J-integral in a welding residual stress field is discussed.

An assessment of the Sachs method for measuring residual stresses in cold worked fastener holes

1998 ◽  
Vol 33 (4) ◽  
pp. 263-274 ◽  
Author(s):  
D J Smith ◽  
C G C Poussard ◽  
M J Pavier
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Cold Working ◽  
Element Model ◽  
Fe Model ◽  
Working Process ◽  
Element Analysis ◽  
Near Surface ◽  
Cold Worked ◽  
Good Agreement

Measurements of residual stresses in 6 mm thick aluminium alloy 2024 plates containing 4 per cent cold worked fastener are made using the Sachs method. The measurements are made on discs extracted from the plates. The measured tangential residual stress distribution adjacent to the hole edge are found to be affected by the disc diameter. The measured residual stresses are also in good agreement with averaged through-thickness predictions of residual stresses from an axisymmetric finite element (FE) model of the cold working process. A finite element analysis is also conducted to simulate disc extraction and then the Sachs method. The measured FE residual stresses from the Sachs simulation are found to be in good agreement with the averaged through-thickness predicted residual stresses. The Sachs simulation was not able to reproduce the detailed near-surface residual stresses found from the finite element model of the cold working process.

Sign in / Sign up

Export Citation Format

Share Document