scholarly journals Modelling of multiple impacts for the prediction of distortions and residual stresses induced by ultrasonic shot peening (USP)

2012 ◽  
Vol 212 (10) ◽  
pp. 2080-2090 ◽  
Author(s):  
Thibaut Chaise ◽  
Jun Li ◽  
Daniel Nélias ◽  
Régis Kubler ◽  
Said Taheri ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Shot Peening ◽  
Multiple Impacts ◽  
Ultrasonic Shot Peening

Effect of Very High Stress Levels on the Fatigue Life of a TiAl Based Alloy

2005 ◽  
Vol 490-491 ◽  
pp. 418-423
Author(s):  
C. Pilé ◽  
Delphine Retraint ◽  
Manuel François ◽  
Jian Lu
Keyword(s):  
Fatigue Life ◽  
Residual Stresses ◽  
Shot Peening ◽  
Treatment Time ◽  
Fatigue Crack Initiation ◽  
High Stress ◽  
Treatment Conditions ◽  
Stress Levels ◽  
Ultrasonic Shot Peening ◽  
Very High

The aim of this work is to use ultrasonic shot peening, a mechanical surface treatment derived from conventional shot peening, in order to increase the fatigue life of TiAl alloys. The goal of this treatment is to generate compressive superficial residual stresses which are aimed to enhance fatigue crack initiation and growth resistance. For this purpose, different ultrasonic shot peening tests have been carried out on Ti-48Al-2Cr-2Nb samples in order to optimise treatment conditions. The first results reveal that it is possible to generate very high stress levels (»1000 MPa) beneath the surface, far much higher than the tensile yield stress of the material which is in the range 350-600 MPa. Such a phenomenon was also observed in ultrasonic shot peened iron or stainless steel and seems to be associated to the creation of a new homogeneous and nanometric structure below the surface of the alloy [1, 2]. In the light of these encouraging results, the shot peening treatment was optimised in terms of residual stresses profile and surface quality. The influence of different parameters of shot peening like the treatment time, the shot diameter as well as the specimen-sonotrode distance were studied. S-N curves were realised on polished specimens as well as on shot peened samples in order to study the effect of the treatment on the fatigue life of this intermetallic alloy.

Modeling of Residual Stresses After Shot Peening and the Effect of Accounting Their Influence on the Stress State of Turbine Blade Fir Tree Roots

2020 ◽  
Author(s):  
Boris Vasilyev ◽  
Nikita Zhukov ◽  
Igor Kiselev ◽  
Alexander Selivanov
Keyword(s):  
Residual Stresses ◽  
Turbine Blade ◽  
Shot Peening ◽  
Strain State ◽  
Multiple Impacts ◽  
Tree Roots ◽  
Turbine Wheel ◽  
Suggested Approach ◽  
Cyclic Durability ◽  
Compressive Residual Stresses

Abstract Numerical modeling approaches have been developed for simulating shot peening processes and consideration of compressive residual stresses when performing strength calculations of turbine wheel joints. A three-stage method is presented to combine strength analyses of turbine blade with the output of LS-DYNA simulations (RS diagrams) of multiple impacts. Predictions of RS distributions obtained using the suggested approach are compared with experimental data and good correlation was achieved. The effect of the RS diagrams obtained using various SP parameters on the stress-strain state of the turbine blade root and the values of its cyclic durability are estimated.

Modelling of Ultrasonic Shot Peening

2015 ◽  
Author(s):  
Vincent Robin ◽  
Philippe Gilles ◽  
Alexandre Brosse ◽  
Thibaut Chaise
Keyword(s):  
Residual Stresses ◽  
Shot Peening ◽  
Surface Defects ◽  
Cold Work ◽  
Operating Conditions ◽  
Negative Effects ◽  
Chemical Treatments ◽  
Ultrasonic Shot Peening ◽  
Component Manufacturing ◽  
Integrity Assessments

Component manufacturing may induce cold work, residual stresses, microstructure changes and even surface defects. This initial condition is usually ignored in component integrity assessments, but can strongly affect its lifetime. For instance, it is well-known that a rough surface finish associated to the presence of tensile residual stresses may favor fatigue damage. In the same manner, cold work and tensile residual stress will assist initiation of Stress Corrosion Cracking (SCC) for susceptible materials. As the manufacturing process can affect the lifetime of the structure, mitigation treatments such as precompressive loadings, chemical treatments, film deposits or coatings may be applied to sensitive areas. The objectives of these complementary operations are to avoid or compensate negative effects of manufacturing consequences. In the industry surface mechanical treatments such as Ultrasonic Shot Peening (USP) are then used in order to improve surface integrity. Even if these mitigation treatments are well known to increase component lifetime regarding corrosion and fatigue damages, a good understanding of their consequences is required to assess their efficiency and perpetuity under operating conditions. Numerical modelling of USP is one solution to simulate the motion of beads in the peening chamber and to predict the level of stresses in the peened part as shown in this paper. This model which gives a better understanding of the effect on surfaces should help the manufacturers to select the best process parameters.

Comparison between conventional shot peening and ultrasonic shot peening

2018 ◽  
Vol 19 (6) ◽  
pp. 603
Author(s):  
Sondes Manchoul ◽  
Rabi Ben Sghaier ◽  
Rawdha Seddik ◽  
Raouf Fathallah
Keyword(s):  
Residual Stresses ◽  
Shot Peening ◽  
Treatment Process ◽  
Three Dimensional ◽  
Surface Characteristics ◽  
Aisi 316L ◽  
Plastic Deformations ◽  
Ultrasonic Shot Peening ◽  
Three Dimensional Models ◽  
Mechanical Surface

Shot peening process is a mechanical surface treatment process widely used in the industry. Ultrasonic shot peening and conventional shot peening are two important mechanisms of this process. This work aims at studying and comparing the influence of conventional shot peening and ultrasonic shot peening on the surface characteristics (residual stresses, equivalent plastic deformations, and roughness). Three-dimensional models are established to simulate the two mechanisms by using the finite elements software ABAQUS/PYTHON. The residual stresses distributions, as well as the roughness and the equivalent plastic deformations of the AISI 2205 and the AISI 316L induced by both models, are predicted and compared.

scholarly journals Influence of Shot Peening on the Isothermal Fatigue Behavior of the Gamma Titanium Aluminide Ti-48Al-2Cr-2Nb at 750 °C

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1083
Author(s):  
Christoph Breuner ◽  
Stefan Guth ◽  
Elias Gall ◽  
Radosław Swadźba ◽  
Jens Gibmeier ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Shot Peening ◽  
Elevated Temperatures ◽  
Stress Amplitude ◽  
Negative Impact ◽  
Fatigue Behavior ◽  
Surface Hardness ◽  
Fatigue Tests ◽  
Positive Effects ◽  
Isothermal Fatigue

One possibility to improve the fatigue life and strength of metallic materials is shot peening. However, at elevated temperatures, the induced residual stresses may relax. To investigate the influence of shot peening on high-temperature fatigue behavior, isothermal fatigue tests were conducted on shot-peened and untreated samples of gamma TiAl 48-2-2 at 750 °C in air. The shot-peened material was characterized using EBSD, microhardness, and residual stress analyses. Shot peening leads to a significant increase in surface hardness and high compressive residual stresses near the surface. Both effects may have a positive influence on lifetime. However, it also leads to surface notches and tensile residual stresses in the bulk material with a negative impact on cyclic lifetime. During fully reversed uniaxial tension-compression fatigue tests (R = −1) at a stress amplitude of 260 MPa, the positive effects dominate, and the fatigue lifetime increases. At a lower stress amplitude of 230 MPa, the negative effect of internal tensile residual stresses dominates, and the lifetime decreases. Shot peening leads to a transition from surface to volume crack initiation if the surface is not damaged by the shots.

Enhanced corrosion resistance of the surface modified Ti-13Nb-13Zr alloy by ultrasonic shot peening

2021 ◽  
pp. 109597
Author(s):  
Pramod Kumar ◽  
G.S. Mahobia ◽  
Sumantra Mandal ◽  
V. Singh ◽  
Kausik Chattopadhyay
Keyword(s):  
Corrosion Resistance ◽  
Shot Peening ◽  
Ultrasonic Shot Peening ◽  
13Zr Alloy ◽  
Surface Modified
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