Laser Shock PeeningProcess and Current Applications
Goran Iveti¢
May 10, 2010
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Contents
1 Laser Shock PeeningProcess OverviewExperimental ActivityNumerical Activity
2 Current state of LSP technologyApplications of LSPLSP technology di�usion
3 ConclusionsSetting up LSP technology
Goran Iveti¢ Laser Shock Peening 2 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Contents
1 Laser Shock PeeningProcess OverviewExperimental ActivityNumerical Activity
2 Current state of LSP technologyApplications of LSPLSP technology di�usion
3 ConclusionsSetting up LSP technology
Goran Iveti¢ Laser Shock Peening 2 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Contents
1 Laser Shock PeeningProcess OverviewExperimental ActivityNumerical Activity
2 Current state of LSP technologyApplications of LSPLSP technology di�usion
3 ConclusionsSetting up LSP technology
Goran Iveti¢ Laser Shock Peening 2 / 48
Laser Shock Peening
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
History of LSP
1960s - First theoretical bases for LSP
1970s - First demonstrations of practical use of LSP
1980s and 90s - Expansion and further development of themethod
2000s - Industrial level applications of the method
Goran Iveti¢ Laser Shock Peening 4 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
History of LSP
1960s - First theoretical bases for LSP
1970s - First demonstrations of practical use of LSP
1980s and 90s - Expansion and further development of themethod
2000s - Industrial level applications of the method
Goran Iveti¢ Laser Shock Peening 4 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
History of LSP
1960s - First theoretical bases for LSP
1970s - First demonstrations of practical use of LSP
1980s and 90s - Expansion and further development of themethod
2000s - Industrial level applications of the method
Goran Iveti¢ Laser Shock Peening 4 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
History of LSP
1960s - First theoretical bases for LSP
1970s - First demonstrations of practical use of LSP
1980s and 90s - Expansion and further development of themethod
2000s - Industrial level applications of the method
Goran Iveti¢ Laser Shock Peening 4 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Physics of LSP
Goran Iveti¢ Laser Shock Peening 5 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Physics of LSP
Goran Iveti¢ Laser Shock Peening 5 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Physics of LSP
Goran Iveti¢ Laser Shock Peening 5 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Physics of LSP
Goran Iveti¢ Laser Shock Peening 5 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Physics of LSP
Goran Iveti¢ Laser Shock Peening 5 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Physics of LSP
Goran Iveti¢ Laser Shock Peening 5 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Physics of LSP
Goran Iveti¢ Laser Shock Peening 5 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Physics of LSP
Goran Iveti¢ Laser Shock Peening 5 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Physics of LSP
Goran Iveti¢ Laser Shock Peening 5 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Applications of LSP on aeronautical structures
Fatigue prone locations of an aircraft
Fuselage skin (riveted joints)
Highly stressed areas of an aircraft structure
Goran Iveti¢ Laser Shock Peening 6 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thin Sheets 2024-T351
Examining the e�ects of Laser Peening on the fatigue life ofthin sheets of 2024-T351 Aluminium Alloy
Experimental tests that have been de�ned in order to evaluatee�ects of di�erent LSP process parameters on the obtaineddistributions of residual stress
The specimens in clad and unclad condition with 2 mmthickness
Goran Iveti¢ Laser Shock Peening 7 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thin Sheets 2024-T351
Examining the e�ects of Laser Peening on the fatigue life ofthin sheets of 2024-T351 Aluminium Alloy
Experimental tests that have been de�ned in order to evaluatee�ects of di�erent LSP process parameters on the obtaineddistributions of residual stress
The specimens in clad and unclad condition with 2 mmthickness
Goran Iveti¢ Laser Shock Peening 7 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thin Sheets 2024-T351
Examining the e�ects of Laser Peening on the fatigue life ofthin sheets of 2024-T351 Aluminium Alloy
Experimental tests that have been de�ned in order to evaluatee�ects of di�erent LSP process parameters on the obtaineddistributions of residual stress
The specimens in clad and unclad condition with 2 mmthickness
Goran Iveti¢ Laser Shock Peening 7 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thin Sheets 2024-T351
E�ect of LSP parameters on the distribution of residual stresses
Investigated parameter E�ect on compressive residual stresses
Laser power density Compressive stresses increase with the increaseof laser power
Number of layers Increasing the number of layers increases thevalue of compressive residual stresses until satu-ration
Peen size Super�cial residual stresses increase with the sizeof the impact and decrease with the plasticallya�ected depth
Pulse Duration Reducing the pulse duration should reducethe depth of the compressive residual stressesthrough the thickness
Goran Iveti¢ Laser Shock Peening 8 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thin Sheets 2024-T351
Laser Shock Peening of clad and unclad sheets
Process settings: laser power density (GW/cm2) - pulseduration (ns) - number of layers
Evaluated settings: 0.5-18-2, 0.5-18-4, 1-18-2, 1-18-4 for cladand unclad specimens (RS measurements by Open University)
Goran Iveti¢ Laser Shock Peening 9 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thin Sheets 2024-T351
Laser Shock Peening of clad and unclad sheets
Process settings: laser power density (GW/cm2) - pulseduration (ns) - number of layers
Evaluated settings: 0.5-18-2, 0.5-18-4, 1-18-2, 1-18-4 for cladand unclad specimens (RS measurements by Open University)
Goran Iveti¢ Laser Shock Peening 9 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thin Sheets 2024-T351
Laser Shock Peening of clad and unclad sheets
Process settings: laser power density (GW/cm2) - pulseduration (ns) - number of layers
Evaluated settings: 0.5-18-2, 0.5-18-4, 1-18-2, 1-18-4 for cladand unclad specimens (RS measurements by Open University)
Goran Iveti¢ Laser Shock Peening 9 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thin Sheets 2024-T351 - Residual stresses
Clad specimen
Goran Iveti¢ Laser Shock Peening 10 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thin Sheets 2024-T351 - Residual stresses
Unclad specimen
Goran Iveti¢ Laser Shock Peening 11 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thin Sheets 2024-T351
Fatigue tests on clad specimens (results by Cran�eld University)
LSPIntensity
DefectDepth
Test 1 Test 2 Average BaselineResults
Di�.
(GW/cm2) (µm) (cycles) (cycles) (cycles) (cycles) %
1 50 91121 91899 91510 62328 47
1 150 22198 21311 21755 18666 17
3 50 69925 81363 75644 62328 21
3 150 15903 17855 16879 18666 -10
Goran Iveti¢ Laser Shock Peening 12 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thick plates 7050-T7451
Examining the e�ects of Laser Peening on the fatigue life ofthick aluminium plates made of a high strength Al alloy, 7050in T7451 condition.
Experimental tests have been de�ned in order to evaluatee�ects of di�erent LSP process parameters on the obtaineddistributions of residual stress
The measurement of residual stresses has been performed byEADS Innovation Works
Goran Iveti¢ Laser Shock Peening 13 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thick plates 7050-T7451
Examining the e�ects of Laser Peening on the fatigue life ofthick aluminium plates made of a high strength Al alloy, 7050in T7451 condition.
Experimental tests have been de�ned in order to evaluatee�ects of di�erent LSP process parameters on the obtaineddistributions of residual stress
The measurement of residual stresses has been performed byEADS Innovation Works
Goran Iveti¢ Laser Shock Peening 13 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thick plates 7050-T7451
Examining the e�ects of Laser Peening on the fatigue life ofthick aluminium plates made of a high strength Al alloy, 7050in T7451 condition.
Experimental tests have been de�ned in order to evaluatee�ects of di�erent LSP process parameters on the obtaineddistributions of residual stress
The measurement of residual stresses has been performed byEADS Innovation Works
Goran Iveti¢ Laser Shock Peening 13 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thick plates 7050-T7451
As in the case of thin aluminium sheets, the LSP processparameters of interest are the same:
laser power densitynumber of layerspeen sizepulse duration
Goran Iveti¢ Laser Shock Peening 14 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thick plates 7050-T7451
As in the case of thin aluminium sheets, the LSP processparameters of interest are the same:
laser power densitynumber of layerspeen sizepulse duration
Goran Iveti¢ Laser Shock Peening 14 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thick plates 7050-T7451
Residual Stresses - Borehole Method
Goran Iveti¢ Laser Shock Peening 15 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thick plates 7050-T7451
Fatigue Tests, R=0.1
Goran Iveti¢ Laser Shock Peening 16 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thick plates 7050-T7451
Fatigue Tests, R=-1
Goran Iveti¢ Laser Shock Peening 17 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Thick plates 7050-T7451
Fatigue Tests, R=-3
Goran Iveti¢ Laser Shock Peening 18 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Shock wave creation and propagation
When a shock wave is created in a solid material, one has totake into account the elastic-plastic properties of the target
Di�erent analytic and numerical models exist that describe theplastic behaviour of metallic materials under high strain loads
The two models found in the literature that are mostcommonly used:
Hugoniot elastic limit (HEL) modelJohnson-Cook �ow stress model
Goran Iveti¢ Laser Shock Peening 19 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Shock wave creation and propagation
When a shock wave is created in a solid material, one has totake into account the elastic-plastic properties of the target
Di�erent analytic and numerical models exist that describe theplastic behaviour of metallic materials under high strain loads
The two models found in the literature that are mostcommonly used:
Hugoniot elastic limit (HEL) modelJohnson-Cook �ow stress model
Goran Iveti¢ Laser Shock Peening 19 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Shock wave creation and propagation
When a shock wave is created in a solid material, one has totake into account the elastic-plastic properties of the target
Di�erent analytic and numerical models exist that describe theplastic behaviour of metallic materials under high strain loads
The two models found in the literature that are mostcommonly used:
Hugoniot elastic limit (HEL) modelJohnson-Cook �ow stress model
Goran Iveti¢ Laser Shock Peening 19 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Shock wave creation and propagation
When a shock wave is created in a solid material, one has totake into account the elastic-plastic properties of the target
Di�erent analytic and numerical models exist that describe theplastic behaviour of metallic materials under high strain loads
The two models found in the literature that are mostcommonly used:
Hugoniot elastic limit (HEL) modelJohnson-Cook �ow stress model
Goran Iveti¢ Laser Shock Peening 19 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Material Models
HEL model
Hugoniot's elastic limit of a material is the compressive yieldstrength of the material under a shock condition that takesinto consideration the increase of the material's yield strengthwith the increase of strain rate
Assuming that the yielding occurs when the stress in the directionof the wave propagation reaches the HEL, the dynamic yieldstrength under uniaxial strain conditions can be de�ned in terms ofthe Hugoniot's elastic limit by:
σy ,dynamic = HEL1− 2ν
1− ν
Goran Iveti¢ Laser Shock Peening 20 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
Material Models
Johnson-Cook �ow stress model
Used for stress-strain dependences at high strain rates (strainrates of up to 106/s)
This material model is purely empirical, the material constants needto be obtained experimentally for each case observed
σ = (A+ Bεneq)
[1 + C ln
( .ε.ε0
)] [1−
(T − T0
Tm − T0
)m]
Goran Iveti¢ Laser Shock Peening 21 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM of LSP
Material models are de�ned
Known input parameters for loading de�nition
Laser intensity (in terms of GW/cm2)Con�ning mediumLaser impulse duration and temporal distributionSpot size
Wanted output parameters used in FEM analysis
Peak pressure (in terms of GPa)Pressure impulse duration and temporal distribution
The FEM analysis is divided in two separate steps
Explicit dynamic analysis of laser impactEquilibrium analysis for springback deformation analysis
Goran Iveti¢ Laser Shock Peening 22 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM of LSP
Material models are de�ned
Known input parameters for loading de�nition
Laser intensity (in terms of GW/cm2)Con�ning mediumLaser impulse duration and temporal distributionSpot size
Wanted output parameters used in FEM analysis
Peak pressure (in terms of GPa)Pressure impulse duration and temporal distribution
The FEM analysis is divided in two separate steps
Explicit dynamic analysis of laser impactEquilibrium analysis for springback deformation analysis
Goran Iveti¢ Laser Shock Peening 22 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM of LSP
Material models are de�ned
Known input parameters for loading de�nition
Laser intensity (in terms of GW/cm2)Con�ning mediumLaser impulse duration and temporal distributionSpot size
Wanted output parameters used in FEM analysis
Peak pressure (in terms of GPa)Pressure impulse duration and temporal distribution
The FEM analysis is divided in two separate steps
Explicit dynamic analysis of laser impactEquilibrium analysis for springback deformation analysis
Goran Iveti¢ Laser Shock Peening 22 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM of LSP
Material models are de�ned
Known input parameters for loading de�nition
Laser intensity (in terms of GW/cm2)Con�ning mediumLaser impulse duration and temporal distributionSpot size
Wanted output parameters used in FEM analysis
Peak pressure (in terms of GPa)Pressure impulse duration and temporal distribution
The FEM analysis is divided in two separate steps
Explicit dynamic analysis of laser impactEquilibrium analysis for springback deformation analysis
Goran Iveti¢ Laser Shock Peening 22 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM of LSP
Material models are de�ned
Known input parameters for loading de�nition
Laser intensity (in terms of GW/cm2)Con�ning mediumLaser impulse duration and temporal distributionSpot size
Wanted output parameters used in FEM analysis
Peak pressure (in terms of GPa)Pressure impulse duration and temporal distribution
The FEM analysis is divided in two separate steps
Explicit dynamic analysis of laser impactEquilibrium analysis for springback deformation analysis
Goran Iveti¢ Laser Shock Peening 22 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM of LSP
Material models are de�ned
Known input parameters for loading de�nition
Laser intensity (in terms of GW/cm2)Con�ning mediumLaser impulse duration and temporal distributionSpot size
Wanted output parameters used in FEM analysis
Peak pressure (in terms of GPa)Pressure impulse duration and temporal distribution
The FEM analysis is divided in two separate steps
Explicit dynamic analysis of laser impactEquilibrium analysis for springback deformation analysis
Goran Iveti¢ Laser Shock Peening 22 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM of LSP
Material models are de�ned
Known input parameters for loading de�nition
Laser intensity (in terms of GW/cm2)Con�ning mediumLaser impulse duration and temporal distributionSpot size
Wanted output parameters used in FEM analysis
Peak pressure (in terms of GPa)Pressure impulse duration and temporal distribution
The FEM analysis is divided in two separate steps
Explicit dynamic analysis of laser impactEquilibrium analysis for springback deformation analysis
Goran Iveti¢ Laser Shock Peening 22 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM Analysis of Thin Sheets 2024-T351
Goran Iveti¢ Laser Shock Peening 23 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM Analysis of Thin Sheets 2024-T351
Experimental vs. FEM results clad
Experimental vs. FEM results unclad
Goran Iveti¢ Laser Shock Peening 24 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM Analysis of Thin Sheets 2024-T351
Experimental vs. FEM results clad
Experimental vs. FEM results unclad
Goran Iveti¢ Laser Shock Peening 24 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM Analysis of Thin Sheets 2024-T351
Alternative process settings - peen depth
Alternative process settings - peen line
Goran Iveti¢ Laser Shock Peening 25 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM Analysis of Thin Sheets 2024-T351
Alternative process settings - peen depth
Alternative process settings - peen line
Goran Iveti¢ Laser Shock Peening 25 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM Analysis of Thick Plates 7050-T7451
Experimental vs. FEM results - peen depth
FEM results - peen line
Goran Iveti¢ Laser Shock Peening 26 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM Analysis of Thick Plates 7050-T7451
Experimental vs. FEM results - peen depth
FEM results - peen line
Goran Iveti¢ Laser Shock Peening 26 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM Analysis of Thick Plates 7050-T7451
FEM Model for Radius E�ect Evaluation
Radius E�ect
Goran Iveti¢ Laser Shock Peening 27 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM Analysis of Thick Plates 7050-T7451
FEM Model for Radius E�ect Evaluation
Radius E�ect
Goran Iveti¢ Laser Shock Peening 27 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM Analysis of Thick Plates 7050-T7451
Alternative pulse durations - single shot
Alternative pulse durations - three shots
Goran Iveti¢ Laser Shock Peening 28 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Process OverviewExperimental ActivityNumerical Activity
FEM Analysis of Thick Plates 7050-T7451
Alternative pulse durations - single shot
Alternative pulse durations - three shots
Goran Iveti¢ Laser Shock Peening 28 / 48
Applications of LSP
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Applications of LSPLSP technology di�usion
Applications of LSP
Jet engine blades
GE (engines for F-16, A320), RR (Trent engines for A340,Boeing 777, 787), P&W (FOD of F119 engines of F22)
For non-aeronautical applications as well - Power GenerationSteam Turbine Blades
Goran Iveti¢ Laser Shock Peening 30 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Applications of LSPLSP technology di�usion
Applications of LSP
LSP at General Electric
Goran Iveti¢ Laser Shock Peening 31 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Applications of LSPLSP technology di�usion
Applications of LSP
Stress corrosion cracking in nuclear reactors
LPwC approach developed by Toshiba
Portable LSP systems developed
Goran Iveti¢ Laser Shock Peening 32 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Applications of LSPLSP technology di�usion
Portable LPwC system
Goran Iveti¢ Laser Shock Peening 33 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Applications of LSPLSP technology di�usion
Applications of LSP
Wing attach lugs F-22
Goran Iveti¢ Laser Shock Peening 34 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Applications of LSPLSP technology di�usion
Applications of LSP
Helicopter Components
Goran Iveti¢ Laser Shock Peening 35 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Applications of LSPLSP technology di�usion
Applications of LSP
Helicopter Components
Goran Iveti¢ Laser Shock Peening 36 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Applications of LSPLSP technology di�usion
Applications of LSP
LSP Forming
MIC laser shock peening is forming the wing skins for the new747-8Laser peen forming can produce compression driven curvaturesin panels with minimal surface roughening not achievable withconventional shot peen forming
Goran Iveti¢ Laser Shock Peening 37 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Applications of LSPLSP technology di�usion
LSP forming
Goran Iveti¢ Laser Shock Peening 38 / 48
Laser Shock PeeningCurrent state of LSP technology
Conclusions
Applications of LSPLSP technology di�usion
Presence of LSP capacities
Goran Iveti¢ Laser Shock Peening 39 / 48
Conclusions
Laser Shock PeeningCurrent state of LSP technology
ConclusionsSetting up LSP technology
Conclusions
Laser Shock Peening
Experimental analyses performed on thin panels have shown greatsensibility on LSP settings, as well as on boundary conditions
Experimental analyses performed on thick plates have shown promisingresults, obtaining compressive residual stresses on the surface of thespecimen that were extended up to ten times more in the depth,compared to shot peened specimen
Developed numerical models showed reasonably good correspondencewith experimental data, qualifying itself for analysis and veri�cation ofLSP processing of thin and aluminium sheets and thick aluminium plates
Alternative process settings proposed for both thin and thick aluminiumplates
Goran Iveti¢ Laser Shock Peening 41 / 48
Laser Shock PeeningCurrent state of LSP technology
ConclusionsSetting up LSP technology
Future Work
Further investigations are necessary in order to determine with moreaccuracy the material constants for Johnson-Cook model (A, B, C, n andm) for materials under shock loading, for all the materials which wereanalysed (2024-T351, 7050-T7451, Aluminium clad)
More research e�orts are necessary in order to improve the LSP of thinsheets, which have shown great sensibility on shock wave re�ections
Goran Iveti¢ Laser Shock Peening 42 / 48
What do we need to start in-house LSP?
Laser Shock PeeningCurrent state of LSP technology
ConclusionsSetting up LSP technology
Necessary equipment
Appropriate laser system
Residual stress measurement capabilities
Fatigue testing capabilities
Metallography capabilities
Goran Iveti¢ Laser Shock Peening 44 / 48
Laser Shock PeeningCurrent state of LSP technology
ConclusionsSetting up LSP technology
Laser Systems
For industrial applications - more than 0.5 kW, 50-100 J, 7-10mm spotsLALP France system: Nd:YAG, 1064 nm, 10 ns, 10 Hz, 3 J(1.5 J, 10 ns, 10 Hz, 532 nm (2 mm impacts))Thales France system: 24 J, 8/15 ns, 5 Hz, 1064 nm, 5-6 mmimpacts (14 J, 532 nm)University of Madrid laser system: Nd:YAG, 1064 nm , 9 ns,10 Hz,2 J, spot 1.5 mm, no coatingToshiba laser system: Nd:YAG, 532 nm, 8 ns, 70-200 mJ, spot0.60.8 mm, up to 100 pulses/mm2
Goran Iveti¢ Laser Shock Peening 45 / 48
Laser Shock PeeningCurrent state of LSP technology
ConclusionsSetting up LSP technology
Residual stress measurement and testing
Hole drilling method
X-ray di�raction
Slitting (crack compliance)
Testing machines
Metallographic analysis
Goran Iveti¢ Laser Shock Peening 46 / 48
Laser Shock PeeningCurrent state of LSP technology
ConclusionsSetting up LSP technology
What can we do?
Assesment of in-house capabilities to meet industry requirements
Research on LSP gives a great opportunity for scienti�c publishing
Goran Iveti¢ Laser Shock Peening 47 / 48
Laser Shock PeeningCurrent state of LSP technology
ConclusionsSetting up LSP technology
LSP Publications
G. Ivetic, I. Meneghin, E. Troiani, Applications and numerical analysis ofLaser Shock Peening as a process for generation of compressive residualstresses, Accepted for presentation at ECRS-8, Riva del Garda, Italy, June26-28 2010.
G. Ivetic, A. Lanciotti, Finite Element analysis of Laser Shock Peening ofAluminium alloy 7050-T7451 thick plates, Presented at the 2nd
International Congress on Laser Peening, San Francisco, USA, April18-21, 2010.
G. Ivetic, A. Lanciotti, Numerical analysis and comparison of ShotPeening and Laser Shock Peening processes, Presented at the 2nd
International Congress on Laser Peening, San Francisco, USA, April18-21, 2010.
G. Ivetic, 3-D FEM Analysis of Laser Shock Peening of Aluminium Alloy2024-T351 Thin Sheets, Accepted for publishing in Surface Engineering,July 26, 2009.
G. Ivetic, A. Lanciotti, FEM Modelling of LSP Process, Laser ShockPeening for Fatigue Life Enhancement Workshop, Airbus UK, June 92009.
Goran Iveti¢ Laser Shock Peening 48 / 48
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