scholarly journals Residual stress in geometric features subjected to laser shock peening

Author(s):  
M Achintha ◽  
D Nowell

This article reports selected findings from a collaborative research study into the fundamental understanding of laser shock peening (LSP), when applied to key airframe and aero-engine alloys. The analyses developed include explicit simulations of the peening process together with a simpler eigenstrain approach, which may be used to provide an approximation to the residual stress field in a number of geometries. These are chosen to represent parts of structural components under conditions relevant to service applications. The article shows that the eigenstrain approach can provide good approximations to the stress field in most circumstances and may provide a computationally efficient tool for exploring different peening strategies. Both explicit and eigenstrain results demonstrate that the interaction between the LSP process and geometric features is important for understanding the subsequent performance of components. Particularly relevant for engineering applications is that not all instances of LSP application may provide an improvement in structural integrity.

2014 ◽  
Vol 34 (4) ◽  
pp. 0414003
Author(s):  
罗密 Luo Mi ◽  
罗开玉 Luo Kaiyu ◽  
王庆伟 Wang Qingwei ◽  
鲁金忠 Lu Jinzhong

2018 ◽  
Vol 7 (4) ◽  
pp. 20170133
Author(s):  
Stefano Coratella ◽  
T. J. Spradlin ◽  
Kristina Langer ◽  
Michael A. Gharghouri ◽  
U. C. Heckenberger ◽  
...  

Author(s):  
Yongxiang Hu ◽  
Zhenqiang Yao ◽  
Jun Hu

Laser shock peening (LSP) is an innovative surface treatment technique similar to shot peening. An analytical model to predict the residual stress field can obtain the impact effect much quickly, and will be invaluable in enabling a close-loop process control in production, saving time and cost of processing. A complete analytical model of LSP with some reasonable simplification is proposed to predict residual stresses in depth by a sequential application of a confined plasma development model and a residual stress model. The spatial distribution of the shock pressure and the high strain rate effect are considered in the model. Good agreements have been shown with several experimental measured results for various laser conditions and target materials, thus proving the validity of the proposed model.


2021 ◽  
pp. 2150029
Author(s):  
XINGQUAN ZHANG ◽  
WENWU NIU ◽  
YUANDE YIN ◽  
JINXIU FANG ◽  
SYED SOHAIL AHMAD SHAH ◽  
...  

Laser shock peening (LSP) was employed to squeeze compressive residual stress (CRS) into the curved surface of the round rod with diameter of 16[Formula: see text]mm. The residual stress field was induced by nine laser shots irradiating at different locations along the specified path. The developing process of the residual stress field was investigated with finite element analysis, and the corresponding experiments were also carried out to validate the calculated results. Results demonstrate that multiple LSP with 50% overlapping rate can result in residual stress field with the maximum CRS varying from 155.2[Formula: see text]MPa to 198.8[Formula: see text]MPa along the direction of the rod axis. The peened surface appears wavy in shape and the maximum depth of plastic deformation in the curved surface is 13.41[Formula: see text][Formula: see text]m. The value of surface roughness increases from 3.87[Formula: see text][Formula: see text]m to 4.65[Formula: see text][Formula: see text]m.


2014 ◽  
Vol 891-892 ◽  
pp. 980-985 ◽  
Author(s):  
Niall Smyth ◽  
Philip E. Irving

This paper reports the effectiveness of residual stress fields induced by laser shock peening (LSP) to recover pristine fatigue life. Scratches 50 and 150 μm deep with 5 μm root radii were introduced into samples of 2024-T351 aluminium sheet 2 mm thick using a diamond tipped tool. LSP was applied along the scratch in a band 5 mm wide. Residual stress fields induced were measured using incremental hole drilling. Compressive residual stress at the surface was-78 MPa increasing to-204 MPa at a depth of 220 μm. Fatigue tests were performed on peened, unpeened, pristine and scribed samples. Scratches reduced fatigue lives by factors up to 22 and LSP restored 74% of pristine life. Unpeened samples fractured at the scratches however peened samples did not fracture at the scratches but instead on the untreated rear face of the samples. Crack initiation still occurred at the root of the scribes on or close to the first load cycle in both peened and unpeened samples. In peened samples the crack at the root of the scribe did not progress to failure, suggesting that residual stress did not affect initiation behaviour but instead FCGR. A residual stress model is presented to predict crack behaviour in peened samples.


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