Laser Shock Peening to Repair, Design and Manufacture Current and Future Aircraft Structures by Residual Stress Engineering

2014 ◽  
Vol 891-892 ◽  
pp. 992-1000 ◽  
Author(s):  
Domenico Furfari
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Crack Growth ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Aircraft Structures ◽  
Area Of Interest ◽  
Aircraft Manufacturing ◽  
Stress Engineering ◽  
Shock Peening

This paper will provide an overview on potential applications for the aerospace industry for repairing aircraft as well as to ensure salvage for identified hot spots in terms of fatigue and crack growth performance. Residual stress engineering is a field of engineering aiming to improve the economic and ecological impact of future aircraft structures by controlling the residual stresses induced by Laser Shock Peening (LSP). Managing the residual stresses for designing structures represents an innovative approach for next generation aircraft. Predicting crack turning induced via a LSP treatment and the optimization of the LSP treatment itself for reaching the crack growth design stress for the targeted weight benefit will be discussed. Advanced forming processes in aircraft manufacturing represent another potential area of interest and the benefits and challenges of applying laser peen forming in this context will be presented. The aeronautical industry requirements for future developments of the laser shock process will also be included for applications ranging from the repair environment to design and manufacturing of aircraft structures.

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.

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 A parametric neutron Bragg edge imaging study of additively manufactured samples treated by laser shock peening

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matteo Busi ◽  
Nikola Kalentics ◽  
Manuel Morgano ◽  
Seth Griffiths ◽  
Anton S. Tremsin ◽  
...  
Keyword(s):  
Residual Stress ◽  
Additive Manufacturing ◽  
Residual Stresses ◽  
Compressive Residual Stress ◽  
Laser Shock Peening ◽  
Powder Bed Fusion ◽  
Laser Shock ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Shock Peening

AbstractLaser powder bed fusion is an additive manufacturing technique extensively used for the production of metallic components. Despite this process has reached a status at which parts are produced with mechanical properties comparable to those from conventional production, it is still prone to introduce detrimental tensile residual stresses towards the surfaces along the building direction, implying negative consequences on fatigue life and resistance to crack formations. Laser shock peening (LSP) is a promising method adopted to compensate tensile residual stresses and to introduce beneficial compressive residual stress on the treated surfaces. Using neutron Bragg edge imaging, we perform a parametric study of LSP applied to 316L steel samples produced by laser powder bed fusion additive manufacturing. We include in the study the novel 3D-LSP technique, where samples are LSP treated also during the building process, at intermediate build layers. The LSP energy and spot overlap were set to either 1.0 or 1.5 J and 40$$\%$$ % or 80$$\%$$ % respectively. The results support the use of 3D-LSP treatment with the higher LSP laser energy and overlap applied, which showed a relative increase of surface compressive residual stress (CRS) and CRS depth by 54$$\%$$ % and 104$$\%$$ % respectively, compared to the conventional LSP treatment.

Application of the Eigenstrain Theory to Predict Residual Stress around Curved Edges after Laser Shock Peening

2013 ◽  
Vol 768-769 ◽  
pp. 185-192 ◽  
Author(s):  
Stefano Coratella ◽  
M. Burak Toparli ◽  
Michael E. Fitzpatrick
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Laser Shock Peening ◽  
Stress Profile ◽  
Laser Shock ◽  
Element Analysis ◽  
Residual Stress Profile ◽  
The Finite Element Analysis ◽  
Treatment Technologies ◽  
Shock Peening

Residual stresses play a fundamental role in mechanical engineering. They can be generated by manufacturing processes or introduced purposely by surface treatment technologies. One of the most recent technologies developed to introduce residual stresses is Laser Shock Peening. Since it is a relatively expensive technology, a fundamental role is played by the Finite Element Analysis approach to predict the final residual stress profile. The FEA approach consists of either direct simulation of the LSP process or the application of the eigenstrain approach. The application of the eigenstrain theory in predicting residual stresses after LSP treatment in curved edges is the subject of this research.

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.

scholarly journals Phase-field modelling for fatigue crack growth under laser shock peening-induced residual stresses

2021 ◽  
Author(s):  
Martha Seiler ◽  
Sören Keller ◽  
Nikolai Kashaev ◽  
Benjamin Klusemann ◽  
Markus Kästner
Keyword(s):  
Growth Rate ◽  
Fatigue Crack ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Crack Growth ◽  
Phase Field ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Fatigue Model ◽  
Shock Peening

AbstractFor the fatigue life of thin-walled components, not only fatigue crack initiation, but also crack growth is decisive. The phase-field method for fracture is a powerful tool to simulate arbitrary crack phenomena. Recently, it has been applied to fatigue fracture. Those models pose an alternative to classical fracture-mechanical approaches for fatigue life estimation. In the first part of this paper, the parameters of a phase-field fatigue model are calibrated and its predictions are compared to results of fatigue crack growth experiments of aluminium sheet material. In the second part, compressive residual stresses are introduced into the components with the help of laser shock peening. It is shown that those residual stresses influence the crack growth rate by retarding and accelerating the crack. In order to study these fatigue mechanisms numerically, a simple strategy to incorporate residual stresses in the phase-field fatigue model is presented and tested with experiments. The study shows that the approach can reproduce the effects of the residual stresses on the crack growth rate.

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.

Numerical Study of Laser Shock Peening Effects on Alloy 600 Nozzles With Initial Residual Stresses

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Ji-Soo Kim ◽  
Hyun-Suk Nam ◽  
Yun-Jae Kim ◽  
Ju-Hee Kim
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Numerical Study ◽  
Laser Shock Peening ◽  
Tensile Residual Stress ◽  
Alloy 600 ◽  
Laser Shock ◽  
Near Surface ◽  
Rate Dependent ◽  
Shock Peening

This paper investigates the effect of initial residual stress and prestrain on residual stresses due to laser shock peening for Alloy 600 using numerical simulation. For simulation, the strain rate dependent Johnson–Cook hardening model with a Mie–Grüneisen equation of state is used. Simulation results are compared with published experimental data, showing good agreement. It is found that the laser shock peening (LSP) process is more effective for higher initial tensile residual stress and for larger initial prestrain in terms of compressive stress at the near surface. However, the effective depth decreases with increasing initial tensile residual stress and initial prestrain.

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