Laser shock waves: A way to test and damage composite materials for aeronautic applications

2012 ◽  
Author(s):  
R. Ecault ◽  
M. Boustie ◽  
L. Berthe ◽  
F. Touchard
Keyword(s):  
Composite Materials ◽  
Shock Waves ◽  
Laser Shock

scholarly journals Investigation of Corrosion Behaviour of Aluminium Alloy Subjected to Laser Shock Peening without a Protective Coating

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
U. Trdan ◽  
J. Grum
Keyword(s):  
Shock Waves ◽  
Protective Coating ◽  
Corrosion Behaviour ◽  
Laser Shock Peening ◽  
Anodic Current Density ◽  
Strain Rates ◽  
Laser Shock ◽  
Near Surface ◽  
Shock Peening ◽  
Chloride Environment

The effect of shock waves and strain hardening of laser shock peening without protective coating (LSPwC) on alloy AA 6082-T651 was investigated. Analysis of residual stresses confirmed high compression in the near surface layer due to the ultrahigh plastic strains and strain rates induced by multiple laser shock waves. Corrosion tests in a chloride environment were carried out to determine resistance to localised attack, which was also verified on SEM/EDS. OCP transients confirmed an improved condition, that is, a more positive and stable potential after LSPwC treatment. Moreover, polarisation resistance of the LSPwC treated specimen was by a factor of 25 higher compared to the untreated specimen. Analysis of voltammograms confirmed an improved enhanced region of passivity and significantly smaller anodic current density of the LSPwC specimen compared to the untreated one. Through SEM, reduction of pitting attack at the LSPwC specimen surface was confirmed, despite its increased roughness.

Laser shock waves as a tool of changing the strains in materials

2000 ◽  
Vol 288 (2) ◽  
pp. 173-176 ◽  
Author(s):  
Y. Nikiforov ◽  
V. Yakovyna ◽  
N. Berchenko
Keyword(s):  
Shock Waves ◽  
Laser Shock

Optical brake induced by laser shock waves

2021 ◽  
pp. 2050010
Author(s):  
Qiao Kang ◽  
Dongyi Shen ◽  
Jie Sun ◽  
Xin Luo ◽  
Wei Liu ◽  
...  
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Optical Method ◽  
Close Contact ◽  
Surface Friction ◽  
Laser Shock ◽  
Free Standing ◽  
Friction Forces ◽  
Optical Levitation ◽  
Contact Surfaces

We demonstrate an optical method to modify friction forces between two close-contact surfaces through laser-induced shock waves, which can strongly enhance surface friction forces in a sandwiched confinement with/without lubricant, due to the increase of pressure arising from excited shock waves. Such enhanced friction can even lead to a rotating rotor’s braking effect. Meanwhile, this shock wave-modified friction force is found to decrease under a free-standing configuration. This technique of optically controllable friction may pave the way for applications in optical levitation, transportation, and microfluidics.

Modelling shock waves in composite materials using generalised orthotropic pressure

2019 ◽  
Vol 32 (4) ◽  
pp. 1217-1229 ◽  
Author(s):  
M. K. Mohd Nor ◽  
C. S. Ho ◽  
N. Ma’at ◽  
M. F. Kamarulzaman
Keyword(s):  
Composite Materials ◽  
Shock Waves

scholarly journals Microcracks, spall and fracture in glass: A study using short pulsed laser shock waves

1998 ◽  
Vol 83 (7) ◽  
pp. 3583-3594 ◽  
Author(s):  
Xin-Zen Li ◽  
M. Nakano ◽  
Y. Yamauchi ◽  
K. Kishida ◽  
K. A. Tanaka
Keyword(s):  
Shock Waves ◽  
Pulsed Laser ◽  
Laser Shock

Numerical Investigation of Opposing Dual Sided Micro Scale Laser Shock Peening

2006 ◽  
Author(s):  
Yajun Fan ◽  
Youneng Wang ◽  
Sinisa Vukelic ◽  
Y. Lawrence Yao
Keyword(s):  
Residual Stress ◽  
Shock Waves ◽  
Laser Shock Peening ◽  
Time Lags ◽  
Laser Shock ◽  
Surface Residual Stress ◽  
Strain Rate Effects ◽  
Micro Scale ◽  
Stress Profiles ◽  
Shock Peening

Laser shock peening (LSP) is an innovative process which imparts compressive residual stresses in the processed surface of metallic parts to significantly improve fatigue life and fatigue strength of this part. In opposing dual sided LSP, the workpiece can be simultaneously irradiated or irradiated with different time lags to create different surface residual stress patterns by virtue of the interaction between the opposing shock waves. In this work, a finite element model, in which the hydrodynamic behavior of the material and the deviatoric behavior including work hardening and strain rate effects were considered was applied to predict residual stress distributions in the processed surface induced under various conditions of the opposing dual sided micro scale laser shock peening. Thus the shock waves from each surface will interact in different ways through the thickness resulting in more complex residual stress profiles. Additionally, when treating a thin section, opposing dual sided peening is expected to avoid harmful effects such as spalling and fracture because the pressures on the opposite surfaces of the target balance one another and prohibit excessive deformation of the target. In order to better understand the wave-wave interactions under different conditions, the residual stress profiles corresponding to various workpiece thicknesses and various irradiation times were evaluated.

Characteristics of High Power Laser Shock Waves and Their Cleaning Performance

2019 ◽  
Vol 11 (2) ◽  
pp. 41-46 ◽  
Author(s):  
Tae-Gon Kim ◽  
Young-Sam Yoo ◽  
Il-Ryong Son ◽  
Deoksuk Jang ◽  
Dongsik Kim ◽  
...  
Keyword(s):  
Shock Waves ◽  
High Power ◽  
Laser Shock ◽  
High Power Laser ◽  
Power Laser ◽  
Cleaning Performance

Numerical Investigation of Opposing Dual Sided Microscale Laser Shock Peening

2006 ◽  
Vol 129 (2) ◽  
pp. 256-264 ◽  
Author(s):  
Yajun Fan ◽  
Youneng Wang ◽  
Sinisa Vukelic ◽  
Y. Lawrence Yao
Keyword(s):  
Residual Stress ◽  
Shock Waves ◽  
Element Model ◽  
Laser Shock Peening ◽  
Time Lags ◽  
Laser Shock ◽  
Surface Residual Stress ◽  
Strain Rate Effects ◽  
Stress Profiles ◽  
Shock Peening

Laser shock peening (LSP) is an innovative process which imparts compressive residual stresses in the processed surface of metallic parts to significantly improve fatigue life and fatigue strength of this part. In opposing dual sided LSP, the workpiece can be simultaneously irradiated or irradiated with different time lags to create different surface residual stress patterns by virtue of the interaction between the opposing shock waves. In this work, a finite element model, in which the hydrodynamic behavior of the material and the deviatoric behavior including work hardening and strain rate effects were considered, was applied to predict residual stress distributions in the processed surface induced under various conditions of the opposing dual sided microscale laser shock peening. Thus the shock waves from each surface will interact in different ways through the thickness resulting in more complex residual stress profiles. Additionally, when treating a thin section, opposing dual sided peening is expected to avoid harmful effects such as spalling and fracture because the pressures on the opposite surfaces of the target balance one another and prohibit excessive deformation of the target. In order to better understand the wave–wave interactions under different conditions, the residual stress profiles corresponding to various workpiece thicknesses and various irradiation times were evaluated.

The Shockwave Response of Thin Composite Materials

2012 ◽  
Author(s):  
Douglas Jahnke ◽  
Yiannis Andreopoulos
Keyword(s):  
Composite Materials ◽  
Shock Waves ◽  
Shock Tube ◽  
Frequency Response ◽  
High Frequency ◽  
Composite Plates ◽  
Image Correlation ◽  
Flat Plates ◽  
High Frequency Response ◽  
Nominal Thickness

Impingement of blast or shock waves on structures is characterized by a substantial transient aerodynamic load that develops over the short time associated with the shock reflection time scale. This mutual interaction between the shock wave and the structure can cause significant deformation of the structure and high strain rates within the material resulting in damage. An experimental investigation was carried out to determine the aeroelastic response of thin flat plates of composite materials during face-on impact with planar shock waves. The experiments were performed in a large-scale shock tube research facility, which had a working section of 12 inches in diameter and a length of 80 ft. Phenolic composite S2-HJ1 plates of 1/8 inch nominal thickness consisting of 12 layers of fibers and epoxy composite S2 plates of 1/8 inch nominal thickness consisting of 10 layers of fibers were tested in the present investigation. Miniature semi-conductor strain-gauges of high frequency response, high speed photography and Digital Image Correlation techniques were employed to measure locally the strain on the exterior side of the plates and high frequency response pressure transducers were used to measure time-dependent wall and total pressure. In order to provide comparison with the response of monolithic material to similar compressive loadings, aluminum and stainless steel plates were also tested under the same conditions. The application of shock loading on the specimen causes significant permanent deformation on the plates which has been measured immediately after the experiment while the specimen is still mounted on the end flange of the shock tube. These experimental data obtained in the present experiments include the measured displacement of the external surface of the plates from their original position in the normal to the plate direction along the radius of the specimen. This displacement is highest at the center of the plate and zero at the location of clamping. The results show that the deformations of the thicker plates are still considerably lower than those obtained in the steel and thinner composite plates although the loading pressure is more than triple in magnitude and the corresponding impulse is about 2.3 times higher. Composite plates were found to suppress several of the modes of the wave patterns while metallic ones demonstrate a rich variety of interacting modes. The frequency content of the strain signals on the surface of composite plates was not always the same with the content of the surface acceleration measured in free vibration experiments.

Distribution of shock waves in composite materials reinforced with glass fiber

2018 ◽  
Author(s):  
M. N. Krivosheina ◽  
E. V. Tuch ◽  
S. V. Kobenko
Keyword(s):  
Composite Materials ◽  
Shock Waves ◽  
Glass Fiber
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