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.

Coupled finite and discrete element shot peening simulation based on Johnson–Cook material model

2020 ◽  
Vol 234 (7) ◽  
pp. 974-987
Author(s):  
Abdulrahaman Shuaibu Ahmad ◽  
Yunxin Wu ◽  
Hai Gong
Keyword(s):  
Residual Stress ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Material Model ◽  
Discrete Element ◽  
Target Interaction ◽  
Simulation Based ◽  
Numerical Tools ◽  
Discrete Element Methods ◽  
The Cost

Shot peening is an essential treatment that produces a beneficial compressive layer on the material’s surface, which significantly improves its fatigue life. To minimizes the cost and resources used in determining the finest shot peening parameters based on the experimental approach, a numerical model capable of computing the induced compressive residual stress accurately is required. Hence, the numerical simulation of the shot peening process with multiple random shots that depict the actual shot peening is presented in this paper. The model is developed using the coupled finite and discrete element methods. The two numerical tools were coupled via code in ABAQUS, whereby shot–shot and shot–target interaction behaviors were accurately included. The induced compressive residual stress was computed due to the multiple random shots impact based on the Johnson–Cook material model. The model was experimentally validated and applied to evaluated the influence of shot velocity, shot size, and angle of impact on the final compressive residual stress.

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.

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.

Experimental and Simulation Method of Introducing Compressive Residual Stress in ASTM A516 Grade 70 Steel

2019 ◽  
Vol 803 ◽  
pp. 27-31
Author(s):  
Mohd Rashdan Isa ◽  
Saiful Naim Sulaiman ◽  
Omar Suliman Zaroog
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Surface Treatment ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Tensile Loading ◽  
Simulation Method ◽  
Single Shot ◽  
Equivalent Amount ◽  
Simulation Procedure

Compressive residual stress below the surface of material could increase fatigue life as it encounters the tensile loading applied on the material during operation. Shot peening process is a common surface treatment to introduce this stress. This study will investigate on how to introduce the same amount of residual stress by simulation using FEM as introduced in experimental shot peening process. Actual shot peening process was done using a particular sets of parameters and FEM with single shot is used to simplify the simulation procedure. Result shows that using a single shot simulation could also introduce the equivalent amount of residual stress as in the experimental multi-shots shot peening process. This value could be used in further study to study the relaxation of the stress after load is being applied.

scholarly journals Stress Relaxation Behavior of Cavitation-Processed Cr–Mo Steel and Ni–Cr–Mo Steel

2019 ◽  
Vol 9 (2) ◽  
pp. 299
Author(s):  
Kumiko Tanaka ◽  
Daichi Shimonishi ◽  
Daisuke Nakagawa ◽  
Masataka Ijiri ◽  
Toshihiko Yoshimura
Keyword(s):  
Residual Stress ◽  
Stress Relaxation ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
High Pressures ◽  
Relaxation Behavior ◽  
Material Surface ◽  
Stress Relaxation Behavior ◽  
Gas Atmosphere ◽  
New Processing

Cr–Mo steel and Ni–Cr–Mo steel have higher strength and hardness than carbon steel, and they are occasionally used in harsh environments where high temperatures and high pressures are simultaneously applied in an oxidizing gas atmosphere. In general, in order to improve the fatigue strength of a material, it is important to impart compressive residual stress to the material surface to improve crack resistance and corrosion resistance. Conventionally, the most famous technique for imparting compressive residual stress by surface modification of a material is shot peening processing. However, in shot peening processing, there is concern that particles adhere to the surface of the material or the surface of the material becomes rough. Therefore, in this study high temperature and high-pressure cavitation was applied and the material surface was processed at the time of collapse. A theoretical and experimental study on a new processing method giving compressive residual stress was carried out. In the present study, we will report stress relaxation behavior due to the heat of cavitation in processed Cr–Mo steel and Ni–Cr–Mo steel.

Effect of Microshot Peening on Surface Characteristics of Spring Steel

2010 ◽  
Vol 654-656 ◽  
pp. 374-377
Author(s):  
Yasunori Harada ◽  
Koji Yoshida
Keyword(s):  
Residual Stress ◽  
Shot Peening ◽  
Compressive Residual Stress ◽  
Cast Steel ◽  
High Hardness ◽  
Surface Characteristics ◽  
Spring Steel ◽  
Cemented Carbide ◽  
High Carbon ◽  
New Type

Shot peening is a surface treatment that improves the performance of engineering components. In conventional shot peening, the medium consists of small spheres, which are usually made of high-carbon cast steel; the diameter of the spheres is in the range from 0.3 to 1.2mm. More recently, however, a new type of microshot has been developed to enhance the peening effect. The diameter of the spheres in the new medium is in the range from 0.02 to 0.15mm. In the present study, the effect of microshot peening on the surface characteristics of spring steel was investigated. The injection method of the microshot was of the compressed air type. The microshots of 0.1mm diameter were high-carbon cast steel and cemented carbide, and the workpiece used was the commercially spring steel JIS-SUP10. The surface roughness, hardness and compressive residual stress of the peened workpieces were measured. The surface layer of the workpieces was sufficiently deformed by microshot peening. A high hardness or residual stress was observed near the surface. The use of hard microshots such as cemented carbide was found to cause a significantly enhanced peening effect for spring steel.

A Study on the Fatigue Characteristics of Al6061-T651 by Shot Peening Velocity

2006 ◽  
Vol 326-328 ◽  
pp. 1093-1096 ◽  
Author(s):  
Won Jo Park ◽  
Sun Chul Huh ◽  
Sung Ho Park
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Fatigue Life ◽  
Shot Peening ◽  
High Speed ◽  
Compressive Residual Stress ◽  
Velocity Increase ◽  
Fatigue Characteristics ◽  
Height Increase ◽  
Small Steel

Small steel ball is utilized in Shot peening process. Called “shot ball” are shot in high speed on the surface of metal. When the shot ball hit the surface, it makes plastic deformation and bounce off, that increase the fatigue life by compressive residual stress on surface. In this study, the results of observation on the tensile strength, hardness, surface roughness, compressive residual stress and fatigue life of a shot peened Al6061-T651 were obtained. Experimental results show that arc height increase tremendously by shot velocity. Also, it shows that surface roughness, hardness, compressive residual stress and fatigue life increase as shot velocity increase.

A Rudimentary Analysis of Improving Fatigue Life of Metals by Shot-Peening

1990 ◽  
Vol 57 (2) ◽  
pp. 307-312 ◽  
Author(s):  
Y. F. Al-Obaid
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Theoretical Analysis ◽  
Shot Peening ◽  
Reasonable Agreement ◽  
Experimental Results ◽  
Single Shot ◽  
Repeated Impact ◽  
Entire Surface ◽  
Complicated Process

In this paper, a rudimentary analysis of improving fatigue life of metals is presented. The process is viewed as one of repeated impact of a stream of hard shots on to a target. The model considers first a single shot impinging upon a target and, on bouncing, it leaves a residual stress below the surface of the target. The problem is then generalized to consider the effect of a stream of shots by assuming their effect to be uniformly distributed over the entire surface. The analysis is highly simplified and it mainly aims at understanding the mechanics of this complicated process. Although rudimentary, the theoretical analysis is seen to be in reasonable agreement with experimental results performed with shots on targets of various materials.

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