Shot peening and peen forming finite element modelling – Towards a quantitative method (original) (raw)
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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.
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.
Ceramic Shot Experimental Demonstration of Intelligent Peen Forming on Aluminium Alloy
2008
Today, peen forming is performed through a step by step peening operation with partial coverage and partial automation. It requires time, experience, controls and correction operations. There is definitely a need for automatic manufacturing of large shaped components such as: wing skin, spar, wing panels... By coupling the existing knowledge of experts, numerical results, and experimental data, with special automatic learning and optimization techniques, CADLM thanks to its Advanced Intelligent Design of Structures System can provides a solution for a fully automatic peen forming process where instructions given to the robot would directly lead to the final required shape. The paper first reports experimental works with ceramic beads on material to built a data base of elementary cases to allow capitalising results and generating rules. Different parameters have been studied such as bead size and velocity and panel thickness. Then reverse problem has been studied: bigger flat panels...
WAGNER:SHOT PEENING O-BK, 2003
For many years controlled shot peening (CSP) was considered as a surface treatment of questionable benefits. This impression was f~~elled by contradictory results from fatigue experiments [1,2]. It is now clear that the performance of CSP in terms of fatigue depends on the balance between its beneficial (compressive residual stress and work hardening) and detrimental effects (surface roughening) [3,4]. Hence, in order to achieve a favourable fatigue performance, the role of those effects has to be analysed and understood. To achieve such undertaking it is essential to consider their interaction with other parameters such as the nature of the target material and the loading conditions. This work brings together two micromechanical models, (i) for notch sensitivity [5] and (ii) for fatigue life [6]. The former assesses the effect of surfxe roughening, whilst the latter incorporates the residual stress distribution ancl work hardening on fatigue life calculations. Combination of the two models allows the determination of the residiral stress distribution to meet specific improvements in fatigue life (improvement life factor, ILF). Using the ILF methodology, the effects of CSP can be scrutinised against stress level, surface roughness and ILF value.
Aluminum Alloys Behavior during Forming
Aluminium Alloys and Composites, 2020
Industrial revolution toward weight reduction and fuel efficiency of the automotive and aerospace vehicles is the major concern to replace heavy metals with light weight metals without affecting much strength. For this, aluminum alloys are the major contributors to those industries. Moreover, aluminum alloys are majorly categorized as 1xxx, 2xxx, 3xxx, 4xxx, 5xxx, 6xxx, 7xxx, and 8xxx based on major alloying elements. Among all, 2xxx, 5xxx, 6xxx, and 7xxx are having majority of applications in the abovementioned industries. For manufacturing any engineering deformable components, forming characteristics are must. Forming behavior of aluminum alloys has been evaluated through different processes including deep drawing, stretching, incremental forming, bending, hydro forming etc., under different process conditions (cold, warm, and hot conditions) and process parameters. Each process has its own process feasibility to evaluate the formability without any forming defects in products. The present chapter discusses a few important processes and their parameter effect on the aluminum alloys through the experimentations and simulation works.
Modeling and Simulation for Aluminium Profile Extrusion
Procedia structural integrity, 2018
During their operation, modern aircraft engine components are subjected to increasingly demanding operating conditions, especially the high pressure turbine (HPT) blades. Such conditions cause these parts to undergo different types of time-dependent degradation, one of which is creep. A model using the finite element method (FEM) was developed, in order to be able to predict the creep behaviour of HPT blades. Flight data records (FDR) for a specific aircraft, provided by a commercial aviation company, were used to obtain thermal and mechanical data for three different flight cycles. In order to create the 3D model needed for the FEM analysis, a HPT blade scrap was scanned, and its chemical composition and material properties were obtained. The data that was gathered was fed into the FEM model and different simulations were run, first with a simplified 3D rectangular block shape, in order to better establish the model, and then with the real 3D mesh obtained from the blade scrap. The overall expected behaviour in terms of displacement was observed, in particular at the trailing edge of the blade. Therefore such a model can be useful in the goal of predicting turbine blade life, given a set of FDR data.
Materials Science and Engineering: A, 2006
This paper presents a numerical simulation of the shot peening process using finite element method. The majority of the controlling parameters of the process have been taken into account. The shot peening loading has been characterised by using energy equivalence between the dynamic impact and a static indentation of a peening shot in the treated surface. The behaviour of the subjected material is supposed to be elastic plastic with damage. An integrated law of the damage proposed by Lemaître and Chaboche has been used. The proposed model leads to obtain the residual stress, the plastic deformation profiles and the surface damage. An application on a shot peened Ni-based super alloy Waspaloy has been carried out. The comparison of the residual stresses, obtained by X-ray diffraction method and by finite element calculation, shows a good correlation. The in-depth profile of the plastic deformations and the superficial damage values are in good agreement with the experimental observations.
2010
The purpose of this work is to model the dynamic microstructure evolution of aluminium alloys during hot metal forming processes such as extrusion. To this end, a phenomenological model based on the physical assumption that evolution of microstructure properties saturates after reaching the steady-state forming conditions is formulated. This model in combination with a thermo-elastic viscoplastic material model is implemented in the Finite Element (FE) software Abaqus. Simulation results for the microstructural development during extrusion as a function of process conditions demonstrate the sensitivity of microstructure development to these conditions. Comparison of the simulation results for the microstructure evolution with corresponding experimental results show good qualitative agreement.
Finite Element Analysis of Laser Peening of Thin Aluminum Structures
Metals
Laser shock peening has become a commonly applied industrial surface treatment, particularly for high-strength steel and titanium components. Effective application to aluminum alloys, especially in the thin sections common in aerospace structures, has proved more challenging. Previous work has shown that some peening conditions can introduce at-surface tensile residual stress in thin Al sections. In this study, we employ finite element modeling to identify the conditions that cause this to occur, and show how these adverse effects can be mitigated through selection of peen parameters and patterning.