Microscale Modeling to Study Shot Peening Effects on Aluminum Alloy

2016 ◽  
Author(s):  
H. Bae ◽  
M. Ramulu ◽  
A. Hossain
Keyword(s):  
Residual Stress ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Single Shot ◽  
Impact Model ◽  
Multiple Impacts ◽  
Residual Stress Field ◽  
Multiple Impact ◽  
Microscale Modeling ◽  
Compressive Residual Stresses

Shot peening is a cold working process used to produce a compressive residual stress to modify mechanical properties of metals. It causes impacting a surface with shots with significant force to create plastic deformation. The compressive residual stresses developed by shot peening process helps to avoid the propagation of micro-cracks exist in surface. Shot peening process is often used in aircraft industries to relieve tensile stresses built up in the grinding process, and replace them with beneficial compressive residual stresses. Shot peening has been developed to increase the fatigue strength of metallic parts. Compressive residual stress and surface hardening induced by shot peening process are found beneficial to increase the fatigue life and the resistance to stress corrosion cracking within the metallic component. Even though shot peening has been used for more than 50 years, a review of published papers indicates a lack of studies in numerical modeling. In particular, the effect of complex shot peening process to predict the target material responds to the multiple impacts of shots is not fully revealed. Most studies have investigated the fundamental mechanism and characteristics of fatigue improvement by single shot peening, and have studied the compressive residual stress induced by single normal impact on the surface of the specimen. However, single impact model is appropriate and efficient for sensitivity studies, local plastic effect, and indentation estimation. It is well known that the residual stress by single shot model is not suitable for practical use. The residual stress field from multi impacts is the resultant sum of all the fields by repeated and progressive impacts. It is not feasible to extrapolate results from the single impact model to a practical shot peening process with multiple impacts. Therefore, this research attempts to conduct a microscale modeling to study the shot peening effects of aluminum alloy responds to single and multiple impacts. First, a single shot impact model, representing single shot peening process, has been developed for the estimation of indentations at different velocities. The numerical simulations has been performed with the finite element software code LS-DYNA. The validations of the numerical simulations has been made from experimentally measured surface roughness data. Once the finite element code of single shot peening model is validated, additional numerical models are developed to simulate multiple shot peening process, using multiple impact shots. The multiple impact model are developed for the estimation of the residual stress field.

Numerical Simulation of Residual Stresses Induced from Shot Peening with Finite Element Method

2013 ◽  
Vol 433-435 ◽  
pp. 1898-1901
Author(s):  
Li Juan Cao ◽  
Shou Ju Li ◽  
Zi Chang Shangguan
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Residual Stress ◽  
Surface Layer ◽  
Residual Stresses ◽  
Shot Peening ◽  
Target Material ◽  
Residual Stress Field ◽  
State Of Stress ◽  
Compressive Residual Stresses

Shot peening is a manufacturing process intended to give components the final shape and to introduce a compressive residual state of stress inside the material in order to increase fatigue life. The modeling and simulation of the residual stress field resulting from the shot peening process are proposed. The behaviour of the peened target material is supposed to be elastic plastic with bilinear characteristics. The results demonstrated the surface layer affected by compressive residual stresses is very thin and the peak is located on the surface.

Polycrystal Plasticity Modeling of Cyclic Residual Stress Relaxation in Shot Peened Martensitic Gear Steel

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Rajesh Prasannavenkatesan ◽  
David L. McDowell
Keyword(s):  
Residual Stress ◽  
Stress Relaxation ◽  
Residual Stresses ◽  
Shot Peening ◽  
Cyclic Plasticity ◽  
Residual Stress Field ◽  
Residual Stress Relaxation ◽  
Gear Steel ◽  
Polycrystal Plasticity ◽  
Compressive Residual Stresses

Using a three-dimensional crystal plasticity model for cyclic deformation of lath martensitic steel, a simplified scheme is adopted to simulate the effects of shot peening on inducing initial compressive residual stresses. The model is utilized to investigate the subsequent cyclic relaxation of compressive residual stresses in shot peened lath martensitic gear steel in the high cycle fatigue (HCF) regime. A strategy is identified to model both shot peening and cyclic loading processes for polycrystalline ensembles. The relaxation of residual stress field during cyclic bending is analyzed for strain ratios Rε=0 and −1 for multiple realizations of polycrystalline microstructure. Cyclic microplasticity in favorably oriented martensite grains is the primary driver for the relaxation of residual stresses in HCF. For the case of Rε=−1, the cyclic plasticity occurs throughout the microstructure (macroplasticity) during the first loading cycle, resulting in substantial relaxation of compressive residual stresses at the surface and certain subsurface depths. The initial magnitude of residual stress is observed to influence the degree (percentage) of relaxation. Describing the differential intergranular yielding is necessary to capture the experimentally observed residual stress relaxation trends.

NUMERICAL SIMULATION FOR SHOT-PEENING BASED ON SPH-COUPLED FEM

2011 ◽  
Vol 08 (04) ◽  
pp. 731-745 ◽  
Author(s):  
JIANMING WANG ◽  
FEIHONG LIU
Keyword(s):  
Residual Stress ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Target Material ◽  
Material Model ◽  
Single Shot ◽  
Fem Modeling ◽  
Contact Algorithm ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

In dealing with shot-peening simulation, existing literatures adopt finite element method (FEM), which establishes models of a single shot or several shots only, thus the effect of a large number of shots repeat impacting and the influence among adjacent shots are ignored. To overcome these disadvantages of FEM models, smoothed particle hydrodynamics (SPH)-coupled FEM modeling is presented, in which the shots are modeled by SPH particles and the target material is modeled by finite elements. The two parts interact through contact algorithm to simulate a number of shots impinging the target. Utilizing this model, a material model for shots is established, the relationships between compressive residual stress and peening frequencies, coverage, and velocities are analyzed. Steady compressive residual stress can be obtained by multiple peening; higher coverage can improve the compressive residual stress; faster velocities can induce greater and deeper maximum residual stress in target subsurface. The simulation results agree well with the existing experimental data. The study would not only provide a new powerful tool for the simulation of shot-peening process, but also be benefit to optimize the operating parameters.

scholarly journals Comparative study: Impact of Ball burnishing and shot peening Process on Aluminium 2024 alloy

2021 ◽  
Vol 23 (08) ◽  
pp. 1768-1775
Author(s):  
◽  
Mahendra Kumara C ◽  
D. Shivalingappa ◽  
Prema. S ◽  
◽  
...  
Keyword(s):  
Residual Stress ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Fluid Pressure ◽  
Ball Burnishing ◽  
Hydraulic Unit ◽  
2024 Alloy ◽  
Burnishing Process ◽  
Aeroengine Components ◽  
Compressive Residual Stresses

Compressive residual stress is the major aspect in the extension of the fatigue life of aeroengine components. In this study, a modified burnishing surface treatment and conventional shot peening process was used was proposed to improve surface integrity characteristics such as surface finish, hardness, and stable, advantageous compressive residual stress in turned Cylindrical Aluminum 2024Specimen. In burnishing process, a rolling rigid spherical HSS ball is pressed across an Aluminum 2024Specimen under definite fluid pressure generated by the hydraulic unit and also shot peening was carried out at a shot velocity of 300 m/s. This research examined the effect of burnishing treatment and shot peening process on beneficial compressive residual stresses.

Three-Dimensional Numerical Simulation of Residual Stresses by Shot-Peening

2009 ◽  
Vol 79-82 ◽  
pp. 1189-1192
Author(s):  
Hong Wei Zhang ◽  
Yi Du Zhang ◽  
Qiong Wu
Keyword(s):  
Residual Stress ◽  
Shot Peening ◽  
Incident Angle ◽  
Three Dimensional ◽  
Single Shot ◽  
Residual Stress Field ◽  
Sensitive Material ◽  
Explicit Analysis ◽  
History Of ◽  
Metallic Parts

Shot peening is a complex cold working process used to improve the fatigue life of metallic parts. This investigation is devoted to the modeling and simulation of the residual stress field resulting from the shot peening process, in which the finite element method was employed using a rate sensitive material. The history of energies during explicit dynamic analysis was discussed and the solution time for explicit analysis was analyzed. For the single shot impact model, the effect of shot velocity, shot size, incident angle was studied. In addition, the effect of repeated impacts on the residual stress within the target plate was studied. Furthermore, the multiple shot impacts of shot peening process were accomplished and the effect of peening coverage was investigated based on different shot models.

Study on the Improvement of Fatigue Crack Growth Performance of 6061-T6 Aluminum Alloy Subject to Laser Shot Peening

2011 ◽  
Vol 464 ◽  
pp. 391-394 ◽  
Author(s):  
Cheng Dong Wang ◽  
Jian Zhong Zhou ◽  
Shu Huang ◽  
X.D. Yang ◽  
Z.C. Xu ◽  
...  
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Crack Growth ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Compact Tension ◽  
Crack Size ◽  
Laser Shot ◽  
Material Surface ◽  
Residual Stress Field

In order to enhance mechanical property and restrain crack growth of 6061-T6 aluminum alloy, laser shot peening (LSP) was employed to induce compressive residual stress and plastic deformation on the surface of metal. The FEA code ABAQUS and MSC. Fatigue were used to simulate crack growth of Compact tension (CT) specimens treated by LSP. The numerical simulation results showed that LSP can effectively inhibit the crack growth, decrease the crack growth rate as well as increase the final crack size, and as a consequence, fatigue life was extended. Adding peening times could get deeper compressive residual stress field which strengthen material surface and restrain crack growth, but the fatigue stress intensity factor threshold decreases.

scholarly journals Small–Scale Experimental Investigation of Fatigue Performance Improvement of Ship Hatch Corner with Shot Peening Treatments by Considering Residual Stress Relaxation

2021 ◽  
Vol 9 (4) ◽  
pp. 419
Author(s):  
Jin Gan ◽  
Zi’ang Gao ◽  
Yiwen Wang ◽  
Zhou Wang ◽  
Weiguo Wu
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Fatigue Life ◽  
Stress Relaxation ◽  
Stress Field ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Fatigue Performance ◽  
Residual Stress Field ◽  
Residual Stress Relaxation

Ship hatch corner is a common structure in a ship and its fatigue problem has always been one of the focuses in ship engineering due to the long–term high–stress concentration state during the ship’s life. For investigating the fatigue life improvement of the ship hatch corner under different shot peening (SP) treatments, a series of fatigue tests, residual stress and surface topography measurements were conducted for SP specimens. Furthermore, the distributions of the surface residual stress are measured with varying numbers of cyclic loads, investigating the residual stress relaxation during cyclic loading. The results show that no matter which SP process parameters are used, the fatigue lives of the shot–peened ship hatch corner specimens are longer than those at unpeened specimens. The relaxation rate of the residual stress mainly depends on the maximum compressive residual stress (σRSmax) and the depth of the maximum compressive residual stress (δmax). The larger the values of σRSmax and δmax, the slower the relaxation rates of the residual stress field. The results imply that the effect of residual stress field and surface roughness should be considered comprehensively to improve the fatigue life of the ship hatch corner with SP treatment. The increase in peening intensity (PI) within a certain range can increase the depth of the compressive residual stress field (CRSF), so the fatigue performance of the ship hatch corner is improved. Once the PI exceeds a certain value, the surface damage caused by the increase in surface roughness will not be offset by the CRSF and the fatigue life cannot be improved optimally. This research provides an approach of fatigue performance enhancement for ship hatch corners in engineering application.

scholarly journals Influence of Residual Stress on Fatigue Design of AISI 304 Stainless Steel

2011 ◽  
Vol 7 (2) ◽  
pp. 44 ◽  
Author(s):  
L. Singh ◽  
R.A. Khan ◽  
M.L. Aggarwal
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Stainless Steel ◽  
Fatigue Strength ◽  
Stress Field ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Residual Stress Field ◽  
Aisi 304 ◽  
Fatigue Design

 Austenitic stainless steel cannot be hardened by any form of heat treatment, in fact, quenching from 10000C merely softens them. They are usually cold worked to increase the hardness. Shot peening is a cold working process that changes micro-structure as well as residual stress in the surface layer. In the present work, the compressive residual stress and fatigue strength of AISI 304 austenitic stainless steel have been evaluated at various shot peening conditions. The improvement in various mechanical properties such as hardness, damping factors and fatigue strength was noticed. Compressive residual stress induced by shot peening varies with cyclic loading due to relaxation of compressive residual stress field. The consideration of relaxed compressive residual stress field instead of original compressive residual stress field provides reliable fatigue design of components. In this paper, the exact reductions in weight and control of mechanical properties due to shot peening process are discussed. 

3D Computational Simulation of Multi-Impact Shot Peening

2012 ◽  
Vol 1485 ◽  
pp. 35-40
Author(s):  
Juan Solórzano-López ◽  
Francisco Alfredo García-Pastor
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Stress Field ◽  
Surface Treatment ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Fatigue Testing ◽  
Computational Simulation ◽  
Target Material ◽  
Residual Stress Field

ABSTRACTShot peening is a widely applied surface treatment in a number of manufacturing processes in several industries including automotive, mechanical and aeronautical. This surface treatment is used with the aim of increasing surface toughness and extending fatigue life. The increased performance during fatigue testing of the peened components is mainly the result of the sub-surface compressive residual stress field resulting from the plastic deformation of the surface layers of the target material, caused by the high-velocity impact of the shot. This compressive residual stress field hinders the propagation and coalescence of cracks during the second stage of fatigue testing, effectively increasing the fatigue life well beyond the expected life of a non-peened component.This paper describes a 3D computational model of spherical projectiles impacting simultaneously upon a flat surface. The multi-impact model was developed in ABAQUS/Explicit using finite element method (FEM) and taking into account controlling parameters such as the velocity of the projectiles, their incidence angle and different impact locations in the target surface. Additionally, a parametric study of the physical properties of the target material was carried out in order to assess the effect of temperature on the residual stress field.The simulation has been able to successfully represent a multi-impact processing scenario, showing the indentation caused by each individual shot, as well as the residual stress field for each impact and the interaction between each one of them. It has been found that there is a beneficial effect on the residual stress field magnitude when shot peening is carried out at a relatively high temperature. The results are discussed in terms of the current shot-peening practice in the local industry and the leading edge developments of new peening technologies. Finally, an improved and affordable processing route to increase the fatigue life of automotive components is suggested.

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