Finite Element Analysis of the Variation in Residual Stress Distribution in Laser Shock Peening of Steels

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Rohit Voothaluru ◽  
C. Richard Liu ◽  
Gary J. Cheng
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Laser Shock Peening ◽  
Treatment Technique ◽  
Stress Distributions ◽  
Laser Shock ◽  
Shock Peening ◽  
The Impact ◽  
Compressive Residual Stresses

Laser shock peening (LSP) is a surface treatment technique similar to conventional shot peening. The laser induced plasma causes plastic deformations and compressive residual stresses that are useful for developing improved properties in the fields of resistance to fatigue, wear or stress corrosion cracking. The actual distribution of residual stresses is extremely important while designing for improved fatigue life using laser shock peening, as fatigue cracks would initiate from the weakest point in the structure. In this paper, the variations in distribution of residual stresses due to laser shock peening are studied with a focus on two materials, annealed 1053 and hardened 52100 AISI steels. A 3D finite element model was developed to study the actual distributions of the residual stresses due to laser shock peening. The effect of hardness on the distribution of the residual stresses and the presence of tensile residual stresses in the surrounding regions of the impact is analyzed. Much larger variations in the residual stress distributions were observed in case of the 1053 steel as compared to hardened 52100 steel. A comprehensive analysis of the simulation results was performed in order to address and explain this behavior. It was observed that the extent of overlap would also affect the variations in the residual stress distributions. The tensile residual stresses present in the areas surrounding the shocked region were also analyzed based upon the extent of overlap and the hardness of the material. It was observed that the ratio of peak tensile to compressive residual stresses developed in 1053 steel was much higher as compared to that in the hardened 52100 steel.

Finite Element Analysis of the Effect of Overlapping Impacts of Laser Shock Peening Within Annealed AISI 1053 Steel

2010 ◽  
Author(s):  
Rohit Voothaluru ◽  
C. Richard Liu
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Laser Shock Peening ◽  
Treatment Technique ◽  
Laser Shock ◽  
Fatigue Wear ◽  
Short Period ◽  
Shock Peening ◽  
Compressive Residual Stresses

Laser shock peening is a surface treatment technique similar to conventional shot peening. The laser induced plasma causes plastic deformations and compressive residual stresses in materials which are useful for developing improved properties in the fields of fatigue, wear or stress corrosion cracking. Finite element method is an efficient tool to predict the mechanical effects and the deformations caused due to laser shock peening, which otherwise are difficult to calculate due to the severe pressure imparted in a very short period of time. This paper presents the calculations performed using ABAQUS, for the simulation of multiple laser shock processing in order to evaluate the residual stress and the deformation of the material. A study of the effect of multiple laser shocks and their extent of overlap on the affected depths and the tensile and compressive residual stresses has been discussed. FEM calculations of residual stress fields and extent of surface deformation in annealed AISI 1053 steel has been investigated along with a study of the distribution of tensile and compressive residual stresses due to the difference in the extent of overlap of the multiple shocks.

Experimental and Numerical Analysis of the Distribution of Residual Stresses Induced by Laser Shock Peening in a 2050-T8 Aluminium Alloy

2011 ◽  
Vol 681 ◽  
pp. 296-302 ◽  
Author(s):  
Neila Hfaiedh ◽  
P. Peyre ◽  
I. Popa ◽  
Vincent Vignal ◽  
Wilfrid Seiler ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Aluminium Alloy ◽  
Residual Stress Distribution ◽  
Laser Shock Peening ◽  
Treatment Technique ◽  
Laser Shock ◽  
X Ray Diffraction ◽  
Shock Peening

Laser shock peening (LSP) is an innovative surface treatment technique successfully applied to improving fatigue performance of metallic material. The specific characteristic of (LSP) is the generation of a low work-hardening and a deep compressive residual stresses mechanically produced by a laser-induced shock wave propagating in the material. The aim of this study is to analyse the residual stress distribution induced by laser peening in 2050-T8 aluminium alloy experimentally by the X-ray diffraction technique (method sin2Y) and numerically, by a finite element numerical modelling. A specific focus was put on the residual stress distribution along the surface of the impacted material.

Effects of Simulation Parameters on Residual Stresses of Inconel Alloy 600 in Finite Element Laser Shock Peening Analysis

2012 ◽  
Author(s):  
Ju Hee Kim ◽  
Ji Soo Kim ◽  
Yun Jae Kim ◽  
Hong Yeol Bae ◽  
Joung Soo Kim
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Pulse Duration ◽  
Laser Shock Peening ◽  
Maximum Pressure ◽  
Alloy 600 ◽  
Laser Shock ◽  
Inconel Alloy ◽  
Shock Peening ◽  
Compressive Residual Stresses

Laser shock peening (LSP) is an innovative surface treatment technique, which is successfully applied to improve fatigue performance of metallic components. After the treatment, the fatigue strength and fatigue life of a metallic material can be increased remarkably owing to the presence of compressive residual stresses in the material. Recently, the incidences of cracking in Alloy 600 small-caliber penetration nozzles (CRDM (control rod drive mechanism) and BMI (bottom mounted instrument)) have increased significantly. The cracking mechanism has been attributed to primary water stress corrosion cracking (PWSCC) and has been shown to be driven by welding residual stresses and operational stresses in the weld region. For this reason, to mitigating weld residual stress, preventive maintenance of BMI nozzles was considered application of laser shock peening process. The present study is to predict the residual stresses distribution along the peening surface and the interior of the target (Inconel alloy 600 steel) induced by single and multiple LSP processes using the finite element method. The simulations were accomplished using a commercial finite element package ABAQUS, employing both explicit and implicit methodologies. Effects of parameters related to finite element simulation of laser shock peening process to determine compressive residual stresses of Inconel alloy 600 steel are discussed, in particular parameters associated with the LSP process, such as the maximum pressure, pressure pulse duration, laser spot size and number of shots. It is found that about 2HEL maximum pressure and a certain range of the pulse duration can produce maximum compressive residual stresses near the surface, and thus proper choices of these parameters are important. But plastically affected depth increase with increasing maximum pressure and pulse duration. For the laser spot size, residual stresses are not affected, provided it is larger than a certain size. Magnitudes of the compressive residual stresses and plastically affected depth are found to increase with increasing number of shots, but the effect is less pronounced for more shots. Thus, the amplitude of the initial tensile residual stresses was remarkably changed by LSP. Additionally, In order to evaluate the influence of initial residual stresses in Inconel alloy 600 steel, the initial condition option was employed in the finite element code.

An Analytical Model to Predict Residual Stress Field Induced by Laser Shock Peening

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Yongxiang Hu ◽  
Zhenqiang Yao ◽  
Jun Hu
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Analytical Model ◽  
Laser Shock Peening ◽  
Treatment Technique ◽  
Laser Shock ◽  
Residual Stress Field ◽  
Proposed Model ◽  
Shock Peening ◽  
The Impact

Laser shock peening (LSP) is an innovative surface treatment technique similar to shot peening. An analytical model to predict the residual stress field can obtain the impact effect much quickly, and will be invaluable in enabling a close-loop process control in production, saving time and cost of processing. A complete analytical model of LSP with some reasonable simplification is proposed to predict residual stresses in depth by a sequential application of a confined plasma development model and a residual stress model. The spatial distribution of the shock pressure and the high strain rate effect are considered in the model. Good agreements have been shown with several experimental measured results for various laser conditions and target materials, thus proving the validity of the proposed model.

scholarly journals Machine Learning-Based Prediction and Optimisation System for Laser Shock Peening

2021 ◽  
Vol 11 (7) ◽  
pp. 2888
Author(s):  
Jino Mathew ◽  
Rohit Kshirsagar ◽  
Suraiya Zabeen ◽  
Niall Smyth ◽  
Stratis Kanarachos ◽  
...  
Keyword(s):  
Machine Learning ◽  
Residual Stress ◽  
Residual Stresses ◽  
Process Parameters ◽  
Intelligent System ◽  
Laser Shock Peening ◽  
Treatment Technique ◽  
Laser Shock ◽  
Process Variables ◽  
Shock Peening

Laser shock peening (LSP) as a surface treatment technique can improve the fatigue life and corrosion resistance of metallic materials by introducing significant compressive residual stresses near the surface. However, LSP-induced residual stresses are known to be dependent on a multitude of factors, such as laser process variables (spot size, pulse width and energy), component geometry, material properties and the peening sequence. In this study, an intelligent system based on machine learning was developed that can predict the residual stress distribution induced by LSP. The system can also be applied to “reverse-optimise” the process parameters. The prediction system was developed using residual stress data derived from incremental hole drilling. We used artificial neural networks (ANNs) within a Bayesian framework to develop a robust prediction model validated using a comprehensive set of case studies. We also studied the relative importance of the LSP process parameters using Garson’s algorithm and parametric studies to understand the response of the residual stresses in laser peening systems as a function of different process variables. Furthermore, this study critically evaluates the developed machine learning models while demonstrating the potential benefits of implementing an intelligent system in prediction and optimisation strategies of the laser shock peening process.

Parametric Study on Single Shot and Overlapping Laser Shock Peening on Various Metals via Modeling and Experiments

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Yunfeng Cao ◽  
Yung C. Shin ◽  
Benxin Wu
Keyword(s):  
Experimental Data ◽  
Residual Stress ◽  
Finite Element ◽  
Element Model ◽  
Substrate Material ◽  
Laser Shock Peening ◽  
Single Shot ◽  
Laser Shock ◽  
3D Finite Element ◽  
Shock Peening

Laser shock peening (LSP) under water confinement regime involves several complicated physical phenomena. Among these phenomena, the interaction between laser and coating material during LSP is very important to the laser-induced residual stress, which has an important effect on the fatigue and corrosion properties of the substrate material. To gain a better understanding of this interaction, a series of experiments, including single shot, single-track overlapping, and multitrack overlapping LSP, has been carried out on various metals with different coatings. A 3D finite element model has also been developed to simulate the LSP process. Combining this with a previously developed confined plasma model, which has been verified by the experimental data from literature, the 3D finite element model is used to predict the residual stresses induced in the substrate material as well as the indentation profile on the substrate surface. The model prediction of indentation profiles is compared with the experimental data. The residual stresses in the depth direction are also validated against the X-ray diffraction measurement data for 4140 steel and Ti–6Al–4V, and good agreements are obtained for both predictions. The effect of process parameters on the residual stress is also investigated both experimentally and theoretically.

scholarly journals An Approach to Predict the Residual Stress-Depth-Profile of Thin Sheet Metal Processed by Laser Shock Peening Without Coating

2021 ◽  
Vol 1135 (1) ◽  
pp. 012025
Author(s):  
Tobias Valentino ◽  
Andreas Stephen ◽  
Tim Radel
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Depth Profile ◽  
Thin Sheet ◽  
Laser Shock Peening ◽  
Stress Profile ◽  
Thin Sheets ◽  
Laser Shock ◽  
Process Step ◽  
Shock Peening

Abstract For conventional laser shock peening, the positive influence of compressive residual stresses on fatigue strength is well understood. To protect the material’s surface from ablation, a sacrificial layer is applied. This, however, leads to an additional process step, which deteriorates its economic efficiency. Thus, laser shock peening without coating (LPwC) is more frequently investigated for industrial applications. However, LPwC increases the thermal impact on the material, which may provoke tensile residual stresses in the surface region. In this regard, understanding the influence of LPwC on the residual stress state and deriving a suitable state, e.g., for subsequent applications or forming operations, result in a design of experiment with numerous residual stress measurements. Residual stress-depth-profiles obtained by X-ray diffraction are time-consuming and cost intensive. Hence, a model is proposed to predict the residual stress-depth-profile of LPwC-processed thin sheets. The analytical model is based on the source stress model and uses experimental results, namely hardness as well as shape change measurements. Sheets made of X5CrNi18-10 and with a thickness of 1 mm are LPwC-processed with a nanosecond fiber laser. In the thermally dominated area where tensile residual stresses are present, the model agrees well with the experimental measurements. Moreover, it is revealed that LPwC leads to a saturation of residual stress level maximum and depth in dependence of pulse energy, repetition rate and number of repetitions. Subsequently, the model is used for tailoring the stress profile of thin sheets by LPwC for subsequent bottom bending.

scholarly journals Coupled Modeling Approach for Laser Shock Peening of AA2198-T3: From Plasma and Shock Wave Simulation to Residual Stress Prediction

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 107
Author(s):  
Vasily Pozdnyakov ◽  
Sören Keller ◽  
Nikolai Kashaev ◽  
Benjamin Klusemann ◽  
Jens Oberrath
Keyword(s):  
Residual Stress ◽  
Laser Pulse ◽  
Protective Coatings ◽  
Global Model ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Coating Materials ◽  
Fe Simulations ◽  
Shock Peening ◽  
The Impact

Laser shock peening (LSP) is a surface modification technique to improve the mechanical properties of metals and alloys, where physical phenomena are difficult to investigate, due to short time scales and extreme physical values. In this regard, simulations can significantly contribute to understand the underlying physics. In this paper, a coupled simulation approach for LSP is presented. A global model of laser–matter–plasma interaction is applied to determine the plasma pressure, which is used as surface loading in finite element (FE) simulations in order to predict residual stress (RS) profiles in the target material. The coupled model is applied to the LSP of AA2198-T3 with water confinement, 3×3mm2 square focus and 20 ns laser pulse duration. This investigation considers the variation in laser pulse energy (3 J and 5 J) and different protective coatings (none, aluminum and steel foil). A sensitivity analysis is conducted to evaluate the impact of parameter inaccuracies of the global model on the resulting RS. Adjustment of the global model to different laser pulse energies and coating materials allows us to compute the temporal pressure distributions to predict RS with FE simulations, which are in good agreement with the measurements.

Laser Shock Peening on a 6056-T4 Aluminium Alloy for Airframe Applications

2014 ◽  
Vol 891-892 ◽  
pp. 974-979 ◽  
Author(s):  
Daniel Glaser ◽  
Claudia Polese ◽  
Rachana D. Bedekar ◽  
Jasper Plaisier ◽  
Sisa Pityana ◽  
...  
Keyword(s):  
Residual Stress ◽  
Laser Pulse ◽  
Fatigue Tests ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
X Ray Diffraction ◽  
Bending Fatigue ◽  
Pulse Density ◽  
Shock Peening ◽  
Compressive Residual Stresses

Laser Shock Peening (LSP) is a material enhancement process used to introduce compressive residual stresses in metallic components. This investigation explored the effects of different combinations of LSP parameters, such as irradiance (GW/cm2) and laser pulse density (spots/mm2), on 3.2 mm thick AA6056-T4 samples, for integral airframe applications. The most significant effects that are introduced by LSP without a protective coating include residual stress and surface roughness, since each laser pulse vaporizes the surface layer of the target. Each of these effects was quantified, whereby residual stress analysis was performed using X-ray diffraction with synchrotron radiation. A series of fully reversed bending fatigue tests was conducted, in order to evaluate fatigue performance enhancements with the aim of identifying LSP parameter influence. Improvement in fatigue life was demonstrated, and failure of samples at the boundary of the LSP treatment was attributed to a balancing tensile residual stress.

Sign in / Sign up

Export Citation Format

Share Document