Laser Shock Peening. Goran Iveti. Process and Current Applications. May 10, 2010

Transcription

1 Process and Current Applications Goran Iveti May 10, 2010

2 Contents Laser Shock Peening 1 Laser Shock Peening 2 Applications of LSP LSP technology diusion 3 Setting up LSP technology Goran Iveti Laser Shock Peening 2 / 48

3 Contents Laser Shock Peening 1 Laser Shock Peening 2 Applications of LSP LSP technology diusion 3 Setting up LSP technology Goran Iveti Laser Shock Peening 2 / 48

4 Contents Laser Shock Peening 1 Laser Shock Peening 2 Applications of LSP LSP technology diusion 3 Setting up LSP technology Goran Iveti Laser Shock Peening 2 / 48

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6 History of LSP Laser Shock Peening 1960s - First theoretical bases for LSP 1970s - First demonstrations of practical use of LSP 1980s and 90s - Expansion and further development of the method 2000s - Industrial level applications of the method Goran Iveti Laser Shock Peening 4 / 48

7 History of LSP Laser Shock Peening 1960s - First theoretical bases for LSP 1970s - First demonstrations of practical use of LSP 1980s and 90s - Expansion and further development of the method 2000s - Industrial level applications of the method Goran Iveti Laser Shock Peening 4 / 48

8 History of LSP Laser Shock Peening 1960s - First theoretical bases for LSP 1970s - First demonstrations of practical use of LSP 1980s and 90s - Expansion and further development of the method 2000s - Industrial level applications of the method Goran Iveti Laser Shock Peening 4 / 48

9 History of LSP Laser Shock Peening 1960s - First theoretical bases for LSP 1970s - First demonstrations of practical use of LSP 1980s and 90s - Expansion and further development of the method 2000s - Industrial level applications of the method Goran Iveti Laser Shock Peening 4 / 48

10 Physics of LSP Laser Shock Peening Goran Iveti Laser Shock Peening 5 / 48

11 Physics of LSP Laser Shock Peening Goran Iveti Laser Shock Peening 5 / 48

12 Physics of LSP Laser Shock Peening Goran Iveti Laser Shock Peening 5 / 48

13 Physics of LSP Laser Shock Peening Goran Iveti Laser Shock Peening 5 / 48

14 Physics of LSP Laser Shock Peening Goran Iveti Laser Shock Peening 5 / 48

15 Physics of LSP Laser Shock Peening Goran Iveti Laser Shock Peening 5 / 48

16 Physics of LSP Laser Shock Peening Goran Iveti Laser Shock Peening 5 / 48

17 Physics of LSP Laser Shock Peening Goran Iveti Laser Shock Peening 5 / 48

18 Physics of LSP Laser Shock Peening Goran Iveti Laser Shock Peening 5 / 48

19 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

20 Thin Sheets 2024-T351 Examining the eects of Laser Peening on the fatigue life of thin sheets of 2024-T351 Aluminium Alloy Experimental tests that have been dened in order to evaluate eects of dierent LSP process parameters on the obtained distributions of residual stress The specimens in clad and unclad condition with 2 mm thickness Goran Iveti Laser Shock Peening 7 / 48

21 Thin Sheets 2024-T351 Examining the eects of Laser Peening on the fatigue life of thin sheets of 2024-T351 Aluminium Alloy Experimental tests that have been dened in order to evaluate eects of dierent LSP process parameters on the obtained distributions of residual stress The specimens in clad and unclad condition with 2 mm thickness Goran Iveti Laser Shock Peening 7 / 48

22 Thin Sheets 2024-T351 Examining the eects of Laser Peening on the fatigue life of thin sheets of 2024-T351 Aluminium Alloy Experimental tests that have been dened in order to evaluate eects of dierent LSP process parameters on the obtained distributions of residual stress The specimens in clad and unclad condition with 2 mm thickness Goran Iveti Laser Shock Peening 7 / 48

23 Thin Sheets 2024-T351 Eect of LSP parameters on the distribution of residual stresses Investigated parameter Eect on compressive residual stresses Laser power density Compressive stresses increase with the increase of laser power Number of layers Increasing the number of layers increases the value of compressive residual stresses until saturation Peen size Supercial residual stresses increase with the size of the impact and decrease with the plastically aected depth Pulse Duration Reducing the pulse duration should reduce the depth of the compressive residual stresses through the thickness Goran Iveti Laser Shock Peening 8 / 48

24 Thin Sheets 2024-T351 Laser Shock Peening of clad and unclad sheets Process settings: laser power density (GW/cm 2 ) - pulse duration (ns) - number of layers Evaluated settings: , , , for clad and unclad specimens (RS measurements by Open University) Goran Iveti Laser Shock Peening 9 / 48

25 Thin Sheets 2024-T351 Laser Shock Peening of clad and unclad sheets Process settings: laser power density (GW/cm 2 ) - pulse duration (ns) - number of layers Evaluated settings: , , , for clad and unclad specimens (RS measurements by Open University) Goran Iveti Laser Shock Peening 9 / 48

26 Thin Sheets 2024-T351 Laser Shock Peening of clad and unclad sheets Process settings: laser power density (GW/cm 2 ) - pulse duration (ns) - number of layers Evaluated settings: , , , for clad and unclad specimens (RS measurements by Open University) Goran Iveti Laser Shock Peening 9 / 48

27 Thin Sheets 2024-T351 - Residual stresses Clad specimen Goran Iveti Laser Shock Peening 10 / 48

28 Thin Sheets 2024-T351 - Residual stresses Unclad specimen Goran Iveti Laser Shock Peening 11 / 48

29 Thin Sheets 2024-T351 Fatigue tests on clad specimens (results by Craneld University) LSP Defect Test 1 Test 2 Average Baseline Di. Intensity Depth Results (GW/cm 2 ) (µm) (cycles) (cycles) (cycles) (cycles) % Goran Iveti Laser Shock Peening 12 / 48

30 Thick plates 7050-T7451 Examining the eects of Laser Peening on the fatigue life of thick aluminium plates made of a high strength Al alloy, 7050 in T7451 condition. Experimental tests have been dened in order to evaluate eects of dierent LSP process parameters on the obtained distributions of residual stress The measurement of residual stresses has been performed by EADS Innovation Works Goran Iveti Laser Shock Peening 13 / 48

31 Thick plates 7050-T7451 Examining the eects of Laser Peening on the fatigue life of thick aluminium plates made of a high strength Al alloy, 7050 in T7451 condition. Experimental tests have been dened in order to evaluate eects of dierent LSP process parameters on the obtained distributions of residual stress The measurement of residual stresses has been performed by EADS Innovation Works Goran Iveti Laser Shock Peening 13 / 48

32 Thick plates 7050-T7451 Examining the eects of Laser Peening on the fatigue life of thick aluminium plates made of a high strength Al alloy, 7050 in T7451 condition. Experimental tests have been dened in order to evaluate eects of dierent LSP process parameters on the obtained distributions of residual stress The measurement of residual stresses has been performed by EADS Innovation Works Goran Iveti Laser Shock Peening 13 / 48

33 Thick plates 7050-T7451 As in the case of thin aluminium sheets, the LSP process parameters of interest are the same: laser power density number of layers peen size pulse duration Goran Iveti Laser Shock Peening 14 / 48

34 Thick plates 7050-T7451 As in the case of thin aluminium sheets, the LSP process parameters of interest are the same: laser power density number of layers peen size pulse duration Goran Iveti Laser Shock Peening 14 / 48

35 Thick plates 7050-T7451 Residual Stresses - Borehole Method Goran Iveti Laser Shock Peening 15 / 48

36 Thick plates 7050-T7451 Fatigue Tests, R=0.1 Goran Iveti Laser Shock Peening 16 / 48

37 Thick plates 7050-T7451 Fatigue Tests, R=-1 Goran Iveti Laser Shock Peening 17 / 48

38 Thick plates 7050-T7451 Fatigue Tests, R=-3 Goran Iveti Laser Shock Peening 18 / 48

39 Shock wave creation and propagation When a shock wave is created in a solid material, one has to take into account the elastic-plastic properties of the target Dierent analytic and numerical models exist that describe the plastic behaviour of metallic materials under high strain loads The two models found in the literature that are most commonly used: Hugoniot elastic limit (HEL) model Johnson-Cook ow stress model Goran Iveti Laser Shock Peening 19 / 48

40 Shock wave creation and propagation When a shock wave is created in a solid material, one has to take into account the elastic-plastic properties of the target Dierent analytic and numerical models exist that describe the plastic behaviour of metallic materials under high strain loads The two models found in the literature that are most commonly used: Hugoniot elastic limit (HEL) model Johnson-Cook ow stress model Goran Iveti Laser Shock Peening 19 / 48

41 Shock wave creation and propagation When a shock wave is created in a solid material, one has to take into account the elastic-plastic properties of the target Dierent analytic and numerical models exist that describe the plastic behaviour of metallic materials under high strain loads The two models found in the literature that are most commonly used: Hugoniot elastic limit (HEL) model Johnson-Cook ow stress model Goran Iveti Laser Shock Peening 19 / 48

42 Shock wave creation and propagation When a shock wave is created in a solid material, one has to take into account the elastic-plastic properties of the target Dierent analytic and numerical models exist that describe the plastic behaviour of metallic materials under high strain loads The two models found in the literature that are most commonly used: Hugoniot elastic limit (HEL) model Johnson-Cook ow stress model Goran Iveti Laser Shock Peening 19 / 48

43 Material Models Laser Shock Peening HEL model Hugoniot's elastic limit of a material is the compressive yield strength of the material under a shock condition that takes into consideration the increase of the material's yield strength with the increase of strain rate Assuming that the yielding occurs when the stress in the direction of the wave propagation reaches the HEL, the dynamic yield strength under uniaxial strain conditions can be dened in terms of the Hugoniot's elastic limit by: σ y,dynamic = HEL 1 2ν 1 ν Goran Iveti Laser Shock Peening 20 / 48

44 Material Models Johnson-Cook ow stress model Used for stress-strain dependences at high strain rates (strain rates of up to 10 6 /s) This material model is purely empirical, the material constants need to be obtained experimentally for each case observed [ (. )] [ ( ɛ σ = (A + Bɛ n eq) 1 + C ln. 1 ɛ 0 T T 0 T m T 0 ) m ] Goran Iveti Laser Shock Peening 21 / 48

45 FEM of LSP Laser Shock Peening Material models are dened Known input parameters for loading denition Laser intensity (in terms of GW/cm 2 ) Conning medium Laser impulse duration and temporal distribution Spot 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 impact Equilibrium analysis for springback deformation analysis Goran Iveti Laser Shock Peening 22 / 48

46 FEM of LSP Laser Shock Peening Material models are dened Known input parameters for loading denition Laser intensity (in terms of GW/cm 2 ) Conning medium Laser impulse duration and temporal distribution Spot 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 impact Equilibrium analysis for springback deformation analysis Goran Iveti Laser Shock Peening 22 / 48

47 FEM of LSP Laser Shock Peening Material models are dened Known input parameters for loading denition Laser intensity (in terms of GW/cm 2 ) Conning medium Laser impulse duration and temporal distribution Spot 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 impact Equilibrium analysis for springback deformation analysis Goran Iveti Laser Shock Peening 22 / 48

48 FEM of LSP Laser Shock Peening Material models are dened Known input parameters for loading denition Laser intensity (in terms of GW/cm 2 ) Conning medium Laser impulse duration and temporal distribution Spot 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 impact Equilibrium analysis for springback deformation analysis Goran Iveti Laser Shock Peening 22 / 48

49 FEM of LSP Laser Shock Peening Material models are dened Known input parameters for loading denition Laser intensity (in terms of GW/cm 2 ) Conning medium Laser impulse duration and temporal distribution Spot 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 impact Equilibrium analysis for springback deformation analysis Goran Iveti Laser Shock Peening 22 / 48

50 FEM of LSP Laser Shock Peening Material models are dened Known input parameters for loading denition Laser intensity (in terms of GW/cm 2 ) Conning medium Laser impulse duration and temporal distribution Spot 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 impact Equilibrium analysis for springback deformation analysis Goran Iveti Laser Shock Peening 22 / 48

51 FEM of LSP Laser Shock Peening Material models are dened Known input parameters for loading denition Laser intensity (in terms of GW/cm 2 ) Conning medium Laser impulse duration and temporal distribution Spot 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 impact Equilibrium analysis for springback deformation analysis Goran Iveti Laser Shock Peening 22 / 48

52 FEM Analysis of Thin Sheets 2024-T351 Goran Iveti Laser Shock Peening 23 / 48

53 FEM Analysis of Thin Sheets 2024-T351 Experimental vs. FEM results clad Experimental vs. FEM results unclad Goran Iveti Laser Shock Peening 24 / 48

54 FEM Analysis of Thin Sheets 2024-T351 Experimental vs. FEM results clad Experimental vs. FEM results unclad Goran Iveti Laser Shock Peening 24 / 48

55 FEM Analysis of Thin Sheets 2024-T351 Alternative process settings - peen depth Alternative process settings - peen line Goran Iveti Laser Shock Peening 25 / 48

56 FEM Analysis of Thin Sheets 2024-T351 Alternative process settings - peen depth Alternative process settings - peen line Goran Iveti Laser Shock Peening 25 / 48

57 FEM Analysis of Thick Plates 7050-T7451 Experimental vs. FEM results - peen depth FEM results - peen line Goran Iveti Laser Shock Peening 26 / 48

58 Laser Shock Peening FEM Analysis of Thick Plates 7050-T7451 Experimental vs. FEM results - peen depth FEM results - peen line Goran Iveti Laser Shock Peening 26 / 48

59 FEM Analysis of Thick Plates 7050-T7451 FEM Model for Radius Eect Evaluation Radius Eect Goran Iveti Laser Shock Peening 27 / 48

60 FEM Analysis of Thick Plates 7050-T7451 FEM Model for Radius Eect Evaluation Radius Eect Goran Iveti Laser Shock Peening 27 / 48

61 FEM Analysis of Thick Plates 7050-T7451 Alternative pulse durations - single shot Alternative pulse durations - three shots Goran Iveti Laser Shock Peening 28 / 48

62 FEM Analysis of Thick Plates 7050-T7451 Alternative pulse durations - single shot Alternative pulse durations - three shots Goran Iveti Laser Shock Peening 28 / 48

63 Applications of LSP

64 Applications of LSP Applications of LSP LSP technology diusion 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 Generation Steam Turbine Blades Goran Iveti Laser Shock Peening 30 / 48

65 Applications of LSP Applications of LSP LSP technology diusion LSP at General Electric Goran Iveti Laser Shock Peening 31 / 48

66 Applications of LSP Applications of LSP LSP technology diusion Stress corrosion cracking in nuclear reactors LPwC approach developed by Toshiba Portable LSP systems developed Goran Iveti Laser Shock Peening 32 / 48

67 Applications of LSP LSP technology diusion Portable LPwC system Goran Iveti Laser Shock Peening 33 / 48

68 Applications of LSP Applications of LSP LSP technology diusion Wing attach lugs F-22 Goran Iveti Laser Shock Peening 34 / 48

69 Applications of LSP Applications of LSP LSP technology diusion Helicopter Components Goran Iveti Laser Shock Peening 35 / 48

70 Applications of LSP Applications of LSP LSP technology diusion Helicopter Components Goran Iveti Laser Shock Peening 36 / 48

71 Applications of LSP Applications of LSP LSP technology diusion LSP Forming MIC laser shock peening is forming the wing skins for the new Laser peen forming can produce compression driven curvatures in panels with minimal surface roughening not achievable with conventional shot peen forming Goran Iveti Laser Shock Peening 37 / 48

72 Applications of LSP LSP technology diusion LSP forming Goran Iveti Laser Shock Peening 38 / 48

73 Presence of LSP capacities Applications of LSP LSP technology diusion Goran Iveti Laser Shock Peening 39 / 48

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75 Laser Shock Peening Setting up LSP technology Laser Shock Peening Experimental analyses performed on thin panels have shown great sensibility on LSP settings, as well as on boundary conditions Experimental analyses performed on thick plates have shown promising results, obtaining compressive residual stresses on the surface of the specimen that were extended up to ten times more in the depth, compared to shot peened specimen Developed numerical models showed reasonably good correspondence with experimental data, qualifying itself for analysis and verication of LSP processing of thin and aluminium sheets and thick aluminium plates Alternative process settings proposed for both thin and thick aluminium plates Goran Iveti Laser Shock Peening 41 / 48

76 Future Work Laser Shock Peening Setting up LSP technology Further investigations are necessary in order to determine with more accuracy the material constants for Johnson-Cook model (A, B, C, n and m) for materials under shock loading, for all the materials which were analysed (2024-T351, 7050-T7451, Aluminium clad) More research eorts are necessary in order to improve the LSP of thin sheets, which have shown great sensibility on shock wave reections Goran Iveti Laser Shock Peening 42 / 48

77 What do we need to start in-house LSP?

78 Necessary equipment Setting up LSP technology Appropriate laser system Residual stress measurement capabilities Fatigue testing capabilities Metallography capabilities Goran Iveti Laser Shock Peening 44 / 48

79 Laser Systems Laser Shock Peening Setting up LSP technology For industrial applications - more than 0.5 kw, J, 7-10 mm spots LALP 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 mm impacts (14 J, 532 nm) University of Madrid laser system: Nd:YAG, 1064 nm, 9 ns, 10 Hz,2 J, spot 1.5 mm, no coating Toshiba laser system: Nd:YAG, 532 nm, 8 ns, mj, spot mm, up to 100 pulses/mm 2 Goran Iveti Laser Shock Peening 45 / 48

80 Setting up LSP technology Residual stress measurement and testing Hole drilling method X-ray diraction Slitting (crack compliance) Testing machines Metallographic analysis Goran Iveti Laser Shock Peening 46 / 48

81 What can we do? Laser Shock Peening Setting up LSP technology Assesment of in-house capabilities to meet industry requirements Research on LSP gives a great opportunity for scientic publishing Goran Iveti Laser Shock Peening 47 / 48

82 LSP Publications Laser Shock Peening Setting up LSP technology G. Ivetic, I. Meneghin, E. Troiani, Applications and numerical analysis of Laser Shock Peening as a process for generation of compressive residual stresses, Accepted for presentation at ECRS-8, Riva del Garda, Italy, June G. Ivetic, A. Lanciotti, Finite Element analysis of Laser Shock Peening of Aluminium alloy 7050-T7451 thick plates, Presented at the 2 nd International Congress on Laser Peening, San Francisco, USA, April 18-21, G. Ivetic, A. Lanciotti, Numerical analysis and comparison of Shot Peening and Laser Shock Peening processes, Presented at the 2 nd International Congress on Laser Peening, San Francisco, USA, April 18-21, G. Ivetic, 3-D FEM Analysis of Laser Shock Peening of Aluminium Alloy 2024-T351 Thin Sheets, Accepted for publishing in Surface Engineering, July 26, G. Ivetic, A. Lanciotti, FEM Modelling of LSP Process, Laser Shock Peening for Fatigue Life Enhancement Workshop, Airbus UK, June Goran Iveti Laser Shock Peening 48 / 48