Finite element modelling of shot peening process: Prediction of the compressive residual stresses, the plastic deformations and the surface integrity (original) (raw)
Related papers
Finite element analysis of residual stress induced by shot peening process
Advances in Engineering Software, 2003
The aircraft industry has only recently begun to explore possible application of welding as an alternative joining method for the design of future large civil airliner wing. One of the main obstacles, encountered in the past years, to welding application within the aircraft industries were due to failure in the weldments, caused by high tensile residual stresses present in the region of the weld, reducing drastically fatigue strength of welded joints. Improvement in the fatigue life of the welded joint can be obtained if compressive residual stresses are introduced at the weld region.Shot peening is a manufacturing process intended to give aircraft structures the final shape and to introduce a compressive residual state of stress inside the material in order to increase fatigue life. This paper presents the modeling and simulation of the residual stress field resulting from the shot peening process. The results achieved show that a significant decrease of welding induced tensile residual stress magnitude can be obtained. Good agreement between experimental and numerical results was achieved.
Effects of Residual Compressive Stresses in the Shot Peening Process
International journal of engineering research and technology, 2014
This work presents the favorable effects of residual compressive stresses during shot peening process by varying different parameters such as shot velocity, shot angle, shot diameters. The shot peening process is largely used for the surface treatment of metallic components with the aim of increasing surface toughness and extending fatigue life. A secondary consequence of the process is that the residual stress distribution developed within the material may induce distortion of the component. This effect may therefore be used constructively in the straightening and forming of thin flexible metallic structures. The various techniques available for modeling the effect of peening with finite elements are discussed. In particular, a method of simulating the effect of peening on large flexible panels is presented. Analyses are shown in which a novel loading is applied to finite element meshes in order to produce the desired residual stress distribution. Results from tests are compared to finite element analyses with DOE and preliminary results of large scale analyses are presented.
2005
This study was performed using the Finite Element Method with the main objective of simulating the shot peening process to evaluate the residual stresses. Shot peening was simulated considering the one single shot impact against a plate throughout an axisymmetric model. An integration explicit dynamic algorithm was employed, taking into consideration the elastic plastic behavior of the two bodies in contact. Slidelines were utilized to simulate the impact zone. The obtained results were compared with values of experimental expressions found in specialized literature. The finite element professional software denominated LUSAS(R) was used in the simulation.
Finite element simulation of shot peening of an aluminum alloy considering hardening models
Russian Journal of Non-Ferrous Metals, 2016
Shot peening is a surface engineering process acknowledged for its potential to develop fatigue strength and erosion-corrosion resistance of metallic materials. In the present study, a 3-D finite element model is employed to predict the effective parameters through a single shot impact and the accuracy of the simulation is validated using previous literatures. In order to induce uniform compressive residual stress patterns across the specimen, processing parameters such as shot velocity, impact angle and friction coefficient should be controlled. It is observed that by increasing the shot velocity and the friction coefficient, the depth of compressive residual stress increases. Moreover, a comparative study between isotropic and kinematic hardening models is performed to evaluate the significant role of the hardening models on the compressive residual stress. It is observed that the kinematic hardening model shows better compatibility with the experimental results compared to the isotropic hardening.
Analytical modelling for residual stresses produced by shot peening
Materials & Design, 2009
In the present work, an analytical model for the residual stresses formed during the shot peening process is analysed. The model employed was proposed by Li and co-workers [Li J et al. Mechanical approach to the residual stress field induced by shot peening. Mater Sci Eng 1991;A147:167-73] and complemented by Shen and co-workers [Shen S et al. Assessment, development and validation of computational fracture mechanics methodologies and tools for shot-peened materials used in rotorcraft principal structural elements [S.I.], 2004]. However, two modifications are adopted: the hertzian pressure is considered as a dynamic load and the Ramberg-Osgood and/or Ludwick constitutive models of the stress-strain curve is adopted to describe the plastic behaviour of the target material. The resulting model is checked using experimental measurements obtained in the literature of residual stresses on a 4140 steel shot peened target as well as on our own data for shot peened Al 7475 alloy.
Investigation of Residual Stresses after Shot Peening Processing
2019
Mechanical surface treatments using an elastic-plastic cold working process can develop residual stresses on the surface of a workpiece. Compressive residual stresses on the surface increase resistance against surface crack propagation, so the overall mechanical performance can be improved by this technique. Compressive residual stresses can be created by different methods such as hammering, rolling, and shot peening. Shot peening is a well-established method to induce compressive residual stresses in the metallic components using cold working, and often ascribed to being beneficial to fatigue life in the aerospace and automobile industries. In this method, the surface is bombarded by high-velocity spherical balls which cause plastic deformation of the substrate, leading to a residual compressive stress after shot peening on the surface of the part. Computational modeling is an appropriate and effective way which can predict the amount of produced residual stresses and plastic defor...
Literature review of numerical simulation and optimisation of the shot peening process
Advances in Mechanical Engineering, 2019
This work provides a comprehensive review of numerical simulation and optimisation of the shot peening found in the existing literature over the past 10 years. The review found that the developed numerical models coupling finite elements with discrete elements became increasingly mature and showed their advantages in incorporating flow behaviour and randomness of shots. High emphasis must be placed on the constitutive equations of target material where its strain-rate sensitivity, cyclic behaviour and Bauschinger effects are recommended to be incorporated in the numerical material model simultaneously since considering one of them in isolation may lead to unreliable distribution of residual stresses. Furthermore, material hardening is a critical benefit of shot peening; however, it has not received its deserved attention from the existing investigations, neither in simulation nor in optimisation. The study found that intensity and coverage are two critical control parameters recommended to be constraints for optimisation of shot peening. Finally, this work also found that developed heuristic algorithms, such as genetic algorithms have recently showed their advantages for searching optimal combinations of peening parameters. It is plausible that in the near future, the synergy of combining these algorithms with approximation models can be expected to gain more attention by researchers.
Shot peening simulation using discrete and finite element methods
Advances in Engineering Software, 2010
Modeling shot peening process is very complex as it involves the interaction of metallic surfaces with a large number of shots of very small diameter. Conventionally such problems are solved using the finite element software (such as ABAQUS) to predict the stresses and strains. However, the number of shots involved and the number of elements required in a real-life components for a 100% coverage that lasts a considerable duration of peening make such an approach impracticable. Ideally, a method that is suitable for obtaining residual compressive stresses (RCS) and the amount of plastic deformations with the least computational effort seems a dire need. In this paper, an attempt has been made to address this issue by using the discrete element method (DEM) in combination with the finite element method (FEM) to obtain reasonably accurate predictions of the residual stresses and plastic strains. In the proposed approach, the spatial information of force versus time from the DEM simulation is utilized in the FE Model to solve the shot peening problem as a transient problem. The results show that the RCS distribution obtained closely matches with that of the computationally intensive direct FEM simulation. It has also been established, in this paper, that this method works well even in the situations where the robust unit cell approaches are found to be difficult to handle.
Dynamic finite element analysis of shot peening process of 2618-T61 aluminium alloy
Scientia Iranica
Shot peening is a surface treatment processes usually used for the improvement of fatigue strength of metallic parts by inducing residual stress field in them. The evaluation of shot peening parameters experimentally is not only very complex but costly as well. An attractive alternative is the explicit dynamics finite element (FE) analysis having the capability of accurately envisaging the shot peening process parameters using a suitable material's constitutive model and numerical technique. In this study, ANSYS/LS-DYNA software was used to simulate the impact of steel shots of various sizes on 2618-T61 aluminium alloy plate described with strain rate dependent elasto-plastic material model. The impacts were carried out at various incident velocities. The effect of shot velocity and size on the induced compressive residual stress and plastic deformation were investigated. The results demonstrated that increasing the shot velocity and size yielded in an increase in plastic deformation of the target. 2 Results obtained were close to the published ones, and the numerical models were capable to capture the pattern of residual stress and plastic deformation observed experimentally in aluminium alloys. The study is quite helpful in determining and selecting optimal shot peening parameters for the surface treatment of aluminium alloy parts.
IJERT-Effects of Residual Compressive Stresses in the Shot Peening Process
International Journal of Engineering Research and Technology (IJERT), 2014
https://www.ijert.org/effects-of-residual-compressive-stresses-in-the-shot-peening-process https://www.ijert.org/research/effects-of-residual-compressive-stresses-in-the-shot-peening-process-IJERTV3IS060398.pdf This work presents the favorable effects of residual compressive stresses during shot peening process by varying different parameters such as shot velocity, shot angle, shot diameters. The shot peening process is largely used for the surface treatment of metallic components with the aim of increasing surface toughness and extending fatigue life. A secondary consequence of the process is that the residual stress distribution developed within the material may induce distortion of the component. This effect may therefore be used constructively in the straightening and forming of thin flexible metallic structures. The various techniques available for modeling the effect of peening with finite elements are discussed. In particular, a method of simulating the effect of peening on large flexible panels is presented. Analyses are shown in which a novel loading is applied to finite element meshes in order to produce the desired residual stress distribution. Results from tests are compared to finite element analyses with DOE and preliminary results of large scale analyses are presented.