scholarly journals Machine Learning Driven Prediction of Residual Stresses for the Shot Peening Process Using a Finite Element Based Grey-Box Model Approach

2021 ◽  
Vol 5 (2) ◽  
pp. 39
Author(s):  
Benjamin James Ralph ◽  
Karin Hartl ◽  
Marcel Sorger ◽  
Andreas Schwarz-Gsaxner ◽  
Martin Stockinger
Keyword(s):  
Machine Learning ◽  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Shot Peening ◽  
Process Model ◽  
Box Model ◽  
Steady Increase ◽  
Process Conditions ◽  
Stress Profile

The shot peening process is a common procedure to enhance fatigue strength on load-bearing components in the metal processing environment. The determination of optimal process parameters is often carried out by costly practical experiments. An efficient method to predict the resulting residual stress profile using different parameters is finite element analysis. However, it is not possible to include all influencing factors of the materials’ physical behavior and the process conditions in a reasonable simulation. Therefore, data-driven models in combination with experimental data tend to generate a significant advantage for the accuracy of the resulting process model. For this reason, this paper describes the development of a grey-box model, using a two-dimensional geometry finite element modeling approach. Based on this model, a Python framework was developed, which is capable of predicting residual stresses for common shot peening scenarios. This white-box-based model serves as an initial state for the machine learning technique introduced in this work. The resulting algorithm is able to add input data from practical residual stress experiments by adapting the initial model, resulting in a steady increase of accuracy. To demonstrate the practical usage, a corresponding Graphical User Interface capable of recommending shot peening parameters based on user-required residual stresses was developed.

Surface Modification Analysis after Shot Peening of AA 7075 in Different States

2013 ◽  
Vol 768-769 ◽  
pp. 519-525 ◽  
Author(s):  
Sebastjan Žagar ◽  
Janez Grum
Keyword(s):  
Residual Stress ◽  
Surface Layer ◽  
Residual Stresses ◽  
Aluminium Alloy ◽  
Shot Peening ◽  
Fatigue Testing ◽  
Stress Profile ◽  
Treatment Conditions ◽  
Stress Profiles ◽  
Compressive Residual Stresses

The paper deals with the effect of different shot peening (SP) treatment conditions on the ENAW 7075-T651 aluminium alloy. Suitable residual stress profile increases the applicability and life cycle of mechanical parts, treated by shot peening. The objective of the research was to establish the optimal parameters of the shot peening treatment of the aluminium alloy in different precipitation hardened states with regard to residual stress profiles in dynamic loading. Main deformations and main residual stresses were calculated on the basis of electrical resistance. The resulting residual stress profiles reveal that stresses throughout the thin surface layer of all shot peened specimens are of compressive nature. The differences can be observed in the depth of shot peening and the profile of compressive residual stresses. Under all treatment conditions, the obtained maximum value of compressive residual stress ranges between -200 MPa and -300 MPa at a depth between 250 μm and 300 μm. Comparison of different temperature-hardened aluminium alloys shows that changes in the Almen intensity values have greater effect than coverage in the depth and profile of compressive residual stresses. Positive stress ratio of R=0.1 was selected. Wöhler curves were determined in the areas of maximum bending loads between 30 - 65 % of material's tensile strength, measured at thinner cross-sections of individual specimens. The results of material fatigue testing differ from the level of shot peening on the surface layer.

Finite Element Thermal/Mechanical Analysis of Transmission Laser Microjoining of Titanium and Polyimide

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Ankitkumar P. Dhorajiya ◽  
Mohammed S. Mayeed ◽  
Gregory W. Auner ◽  
Ronald J. Baird ◽  
Golam M. Newaz ◽  
...  
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Dissimilar Materials ◽  
Optical Microscope ◽  
Mechanical Analysis ◽  
Maximum Temperature ◽  
Stress Profile ◽  
Residual Stress Profile ◽  
Thermal Mechanical Analysis

Detailed analysis of a residual stress profile due to laser microjoining of two dissimilar biocompatible materials, polyimide (PI) and titanium (Ti), is vital for the long-term application of bio-implants. In this work, a comprehensive three-dimensional (3D) transient model for sequentially coupled thermal/mechanical analysis of transmission laser (laser beam with wavelength of 1100 nm and diameter of 0.2 mm) microjoining of two dissimilar materials has been developed by using the finite element code ABAQUS, along with a moving Gaussian laser heat source. First the model has been used to optimize the laser parameters like laser traveling speed and power to obtain good bonding (burnout temperature of PI>maximum temperature of PI achieved during heating>melting temperature of PI) and a good combination has been found to be 100 mm/min and 3.14 W for a joint-length of 6.5 mm as supported by the experiment. The developed computational model has been observed to generate a bonding zone that is similar in width (0.33 mm) to the bond width of the Ti/PI joint observed experimentally by an optical microscope. The maximum temperatures measured at three locations by thermocouples have also been found to be similar to those observed computationally. After these verifications, the residual stress profile of the laser microjoint (100 mm/min and 3.14 W) has been calculated using the developed model with the system cooling down to room temperature. The residual stress profiles on the PI surface have shown low value near the centerline of the laser travel, increased to higher values at about 165 μm from the centerline symmetrically at both sides, and to the contrary, have shown higher values near the centerline on the Ti surface. Maximum residual stresses on both the Ti and PI surfaces are obtained at the end of laser travel, and are in the orders of the yield stresses of the respective materials. It has been explained that the patterned accumulation of residual stresses is due to the thermal expansion and contraction mismatches between the dissimilar materials at the opposite sides of the bond along with the melting and softening of PI during the joining process.

scholarly journals On the Accuracy of Finite Element Models Predicting Residual Stresses in Quenched Stainless Steel

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1308 ◽  
Author(s):  
Israel Medina-Juárez ◽  
Jeferson Araujo de Oliveira ◽  
Richard J. Moat ◽  
Francisco Alfredo García-Pastor
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stainless Steel ◽  
Residual Stresses ◽  
Contour Method ◽  
Stress Profile ◽  
304L Stainless Steel ◽  
Fem Model ◽  
Residual Stress Profile ◽  
Industry Applications

Prediction of residual stress profiles after quenching is important for a range of industry applications. Finite element method (FEM) models have the capability of simulate the cooling and stress evolution during quenching; however, they are very dependent on the heat transfer coefficient (HTC) imposed on the surface. In this paper, an analysis of the HTC effect on the accuracy of the residual stress profile after quenching a 304L stainless steel Jominy sample was conducted. The FEM model was validated in its thermal accuracy using thermocouples and the residual stress profile was measured using the contour method. The results show that a thermally validated FEM model may yield results which overestimate the tensile residual stress and underestimates the compressive residual stress maxima while accurately calculating the maxima positions from the quenched edge. The FEM model accuracy was not improved by modifying the HTC or by using a different thermal expansion coefficient. The results are discussed in terms of the effect of plasticity due to twinning in the residual stresses calculated by the FEM model.

On the convergence of solid meshes for the prediction of part distortions due to residual stresses

2019 ◽  
Vol 233 (17) ◽  
pp. 6209-6217
Author(s):  
JCR Albino ◽  
LA Gonçalves Junior ◽  
VE Beal
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Stable Condition ◽  
Production Costs ◽  
Raw Material ◽  
Rolled Plate ◽  
Internal Stresses ◽  
Stress Profile ◽  
Residual Stress Profile

Residual stresses in rolled plates, used as raw material for the fabrication of aircraft components, arise from manufacturing processes such as rolling, casting, quenching, stretching, and thermal treatments. After each process, the rolled plate has a geometrically stable condition but with internal stresses. However, during part machining an unbalance in the distribution of residual stresses occurs, in special for aircraft components, due to the large amount of material removal throughout the process. This condition of instability leads to component distortions so that any corrective action affects the manufacturing lead-time and production costs. Part distortions are usually predicted by finite element analyses with linear tetrahedral meshes in which the residual stress profiles are applied as a constant value element-wise. In this work, both linear and quadratic solid meshes are employed to address this problem. For this purpose, a Python-based routine is implemented to apply the residual stress profile at the integration points of the elements. Then, finite element simulations of simple geometric configurations (plates and beams) under theoretical and real residual stress distributions are carried out. Performance and effectiveness of two different meshes—tetrahedral and hexahedral (brick-type)—are checked through comparison with results presented by classical plate and beam theories. A general good correlation for the deflections predicted by them is reached.

Numerical evaluation of the residual stresses in shot peening of alloy steels

2021 ◽  
Author(s):  
Mahenk Kumar Patanaik ◽  
Gaurav Tiwari ◽  
Akshay R Govande ◽  
B Ratna Sunil ◽  
Ravikumar Dumpala
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Numerical Study ◽  
Surface Region ◽  
Residual Stress Distribution ◽  
Target Plate

Abstract In the present numerical study, the residual stresses generated during the shot peening process were evaluated using the finite element method. The influence of shot velocity on the residual stress distribution due to the indentation of a rigid shot over the target plate of alloy steel was studied. The finite element package ABAQUS 6.20 is used for simulating the shot peening process considering the target plate to be deformable. A parametric study was performed by introducing strain hardening rate as H1 = 800 MPa, keeping the dimension of target plate same with variation in shot velocity 20, 50, 75, 100, 125, and 150 m/s to check the behavior of residual stress distribution. As the indentation takes place over the metallic target plate, elastic-plastic deformation was observed. The indentation of the shot with a different velocity range causes the difference in the depth and size of the dent and induces the compressive residual stress. For perfectly plastic and the strain hardened material, the residual stress contour was simulated. The simulated results for strain hardened material show the significant change in the compressive residual stress in the sub-surface region of the target plate. It is evident from the results that the shot velocity has a significant effect on the residual stress distribution. The maximum compressive residual stress is achieved when the shot is indented at a velocity of 125 m/s.

Finite Element Simulation of the Residual Stress States after Shot Peening

2006 ◽  
Vol 524-525 ◽  
pp. 349-354 ◽  
Author(s):  
Manuel Klemenz ◽  
Volker Schulze ◽  
Otmar Vöhringer ◽  
Detlef Löhe
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Shot Peening ◽  
Three Dimensional ◽  
Material Model ◽  
Stress Profile ◽  
Viscoplastic Material ◽  
Residual Stress Profile ◽  
Element Simulation

In a three-dimensional Finite-Element-Simulation of shot peening, a combined isotropickinematic viscoplastic material description was introduced in order to describe the cyclic softening effects during peening. After verifying the model in the simulation of push-pull tests at different strain amplitudes it could be used for the shot peening simulation. The simulated residual stress profile is compared with experimental results determined by X-ray diffraction and with simulated results of a simpler isotropic viscoplastic material model.

Local Stress Variations at Bead Interruptions in Austenitic Multi-Pass Groove Welds

2009 ◽  
Author(s):  
Christopher M. Gill ◽  
Paul Hurrell ◽  
John Francis ◽  
Mark Turski
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Good Practice ◽  
304 Stainless Steel ◽  
Stress Profile ◽  
Stress Distributions ◽  
Fe Modelling ◽  
Stress Profiles

This paper presents finite element analyses of residual stress in an austenitic multi-pass groove weld. The aim was to establish the effect upon the residual stress of stop-start interruptions during the deposition of weld beads. Comparison of measured residual stress profiles with the residual stress distributions predicted by finite element (FE) modelling aimed to validate the FE method for predicting residual stresses around stop-start features. This paper presents a comparison of measured and modelled residual stress distributions in a series of simple welded 304 stainless steel plates. The plates were machined with a v-groove designed to be filled using eight weld passes. Samples which included interrupted weld beads contained two stop-start features in the fifth pass. In the first feature the welding power was ramped down over 15 seconds; this represented normal welding good practice. The second feature investigated was an abrupt stop, where the welding power was removed instantaneously; this represented an extreme stop. Three welded plates were considered. One contained five weld passes, such that the final pass contained stop-start features and resulted in partially filling the weld groove. Two welds plates each containing eight passes have also been considered; one contained stop-start features in the fifth pass and the other contained no stop-start features. This allowed a comparison of the effect of stop-start features and the effect that subsequent beads have upon any perturbations in the residual stresses produced. Residual stress measurements have been performed using neutron diffraction. 3D weld modelling has been carried out using VFT and the Abaqus finite element package. Results from the welding FE analyses were compared with the neutron diffraction measurements. Good agreement between the modelled and measured residual stresses is achieved in the uninterrupted 8-pass sample and after deposition of the bead containing stop-start features in the 5-pass sample. Following deposition of subseqeunt beads perturbations in the residual stress profile are retained in the neutron diffraction measurements, but all perturbations are removed from the residual stress profiles predicted using both VFT and Sysweld. This work suggests that modelling welding stop-start features is only necessary in the final weld capping passes, if residual stresses over a short length scale are of interest.

Influence of Shot Peening Parameters on Process Effectiveness

2012 ◽  
Author(s):  
Abdalla Elbella ◽  
Fawaz Fadul ◽  
Sri Harsha Uddanda ◽  
Nagender Reddy Kasarla
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Process Parameters ◽  
Shot Peening ◽  
Incidence Angle ◽  
Target Material ◽  
Stress Profile ◽  
Surface Strength ◽  
Residual Stress Profile ◽  
The Impact

The shot peening process is known for the surface treatment of metallic components. The process is used to enhance surface strength and extend component fatigue life by introducing a compressive residual stress pattern in the surface layers of the component. Numerical simulation of the shot peening process is a tool that has been recently used to help control the process. The simulation helps in investigating the effects of the process parameters with an aim of attaining the optimum residual stress profile and maximum process gain. In this paper, elasto-plastic finite element simulation is used to perform this investigative analysis. The process parameters that are varied in this analysis are: the shot diameter, shot velocity, incidence angle and target material. The analysis is to be carried for three different materials, namely, steel, aluminum and titanium. An Explicit commercial finite element code (ABAQUS) is used to simulate the impact phenomenon. The results of the analysis are sets of varying plots of residual stress through the depth of the targets.

A Sensitivity Analysis of Shot Peening Parameters

2006 ◽  
Author(s):  
Abdalla Elbella ◽  
Vishal Rami ◽  
Jyothi Hogirala
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Process Parameters ◽  
Shot Peening ◽  
Target Material ◽  
Element Model ◽  
Stress Profile ◽  
Explicit Finite Element ◽  
Residual Stress Profile ◽  
Subsurface Layers

Shot peening process is largely used for surface treatment of metallic components with the aim of increasing surface toughness and extending fatigue life. The fatigue strength of the component can be improved by inducing compressive residual stress in the surface and subsurface layers by the shot peening process. Numerical simulation of the shot peening process is an important tool that is used to aid in understanding the effects of the process parameters on intended goal of attaining the optimum residual stress profile and maximum process gain. In this paper an elasto-plastic finite element model is used for the shot peening process. The process parameters that are varied in this analysis are: the shot diameter, shot speed, number of shots at a given time (coverage) and target material. The analysis is carried out for two different materials, namely, steel and aluminum. An Explicit finite element code (ABAQUS) is used to perform this task. These parameters have different effects on the resulting residual profile and the results of the study showed that by adjusting these parameters, the most effective residual stress profile could be obtained.

Finite element modeling of residual stress profile patterns in hard turning

2009 ◽  
Vol 24 (S1) ◽  
pp. S22-S25
Author(s):  
Y. B. Guo ◽  
S. Anurag
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Finite Element Modeling ◽  
Hard Turning ◽  
Internal State ◽  
Stress Profile ◽  
Surface Residual Stress ◽  
Mechanical Coupling ◽  
Element Modeling ◽  
Stress Profiles

Hard turning, i.e., turning hardened steels, may produce the unique “hook” shaped residual stress (RS) profile characterized by surface compressive RS and subsurface maximum compressive RS. However, the formation mechanism of the unique RS profile is not yet known. In this study, a novel hybrid finite element modeling approach based on thermal-mechanical coupling and internal state variable plasticity model has been developed to predict the unique RS profile patterns by hard turning AISI 52100 steel (62 HRc). The most important controlling factor for the unique characteristics of residual stress profiles has been identified. The transition of maximum residual stress at the surface to the subsurface has been recovered by controlling the plowed depth. The predicted characteristics of residual stress profiles favorably agree with the measured ones. In addition, friction coefficient only affects the magnitude of surface residual stress but not the basic shape of residual stress profiles.

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