Simulation of ultrasonic guided wave inspection in CIVA software platform

Transcription

1 Simulation of ultrasonic guided wave inspection in CIVA software platform B. CHAPUIS, K. JEZZINE, V. BARONIAN, D. SEGUR and A. LHEMERY 18 April 2012

2 CIVA: Software for NDT Generalities WHY USING SIMULATION IN NDT? Design of new methods and probes (e.g. phased arrays) Qualification of methods, performance demonstration Interpretation of complex results, diagnosis «Virtual testing» in product design phases Training CIVA: SIMULATION FOR NDT Multi-technique platform: UT, ET, RT-CT Guided Waves Experimental validation within international benchmarks UT : Transmitted beam computation ET : 2D map of a complex defect RT : weld inspection CT : tomographic reconstruction of complex parts Developed by 4 labs at CEA-LIST ~ 25 permanent developers 2

3 CIVA: Software for NDT Generalities SEMI-ANALYTICAL MODELS Based on simplified hypothesis and/or approximations Numerical performances (fast computations) and easy to use Accurate and reliable (validated) predictions for a wide range of situations Possible intensive use in an industrial environment Possible coupling with purely numerical approaches (FDTD, FEM ) IMPLEMENTATION OF A CIVA SOFTWARE PLATFORM A unique set of NDT oriented GUIs, for all techniques Connection to CAD tools In the same environment: Simulation, imaging and processing tools 3

4 OUTLINE Functionalities of CIVA GW 10 Mode computation Field computation Defect response Current developments 2D CAD waveguides Arbitrary defects 4

5 First version of CIVA GW Different modules THREE MODULES Mode computation Display of dispersion curves (phase/group velocity & attenuation) Display of displacement/stress profile in the cross-section Information on the modes possibly propagating in the guide Field computation Visualization of displacement/stress field emitted by a transducer Display of dispersion curves in the bandwidth of the transducer Display of the modal amplitude generated by the transducer Applications: mode selection, design of sensors Defect response (restricted to normal cracks) Display of Ascan Display of dispersion curves in the bandwidth of the transducer Display of the modal amplitude generated/detected by the transducer and diffracted by the defect Response of a crack to one or several modes 5

6 First version of CIVA GW Functionalities Specimens plates (2D computation: Lamb/SH wave) pipes/cylinders (2D and 3D computation) multilayered (no immersed or embedded guides) no arbitrary 2D CAD cross-section (ex: rail) Materials isotropic solid attenuation law: linear with frequency Transducers contact with or without wedge encircling/encircled probes (phased arrays) different type of solicitations pulse-echo/pitch catch configurations Flaws cracks orthogonal to the guide axis 6

7 OUTLINE Functionalities of CIVA GW 10 Mode computation Field computation Defect response Current developments 2D CAD waveguides Arbitrary defects 7

8 Modes of a pipe : influence of coating Geometry and frequency range ½ mm viscoelastic coating (protective layer) 8

9 Modes of a pipe : influence of coating Material parameters steel pipe viscoelastic coating 9

10 Modes of a pipe : influence of coating Dispersion curves with coating without coating 10

11 Modes of a pipe : influence of coating Dispersion curves with coating At 100 khz with coating : Ve = mm/µs Att = db/m without coating u r without coating Ve = mm/µs Att = 0 db/m 11

12 Modes of a pipe : influence of coating Dispersion curves with coating u without coating Torsional mode propagating in the coating 12

13 OUTLINE Functionalities of CIVA GW 10 Mode computation Field computation Defect response Current developments 2D CAD waveguides Arbitrary defects 13

14 Field computation Generation of Lamb modes with a wedge transducer Civa simulation Experimental measurement by Terrien Configuration N. Terrien, D. Osmont, D. Royer, F. Lepoutre and A. Déom, A combined finite element and modal decomposition method to study the interaction of Lamb modes with micro-defects, Ultrasonics,

15 Field computation Phased array capabilities 1.5 m Section on which the field is computed Multi-element probe and associated delay (and amplitude) laws Manual definition of the laws 15

16 Field computation Visualization of the focusing in the pipe 1.5 m Section on which the field is computed Multi-element probe and associated delay (and amplitude) laws Uy axial component 16

17 OUTLINE Functionalities of CIVA GW 10 Mode computation Field computation Defect response Current developments 2D CAD waveguides Arbitrary defects 17

18 Defect response computation Sectorial ring in a pipe The defect is perpendicular to the waveguide axis 18

19 Defect response Focusing 1.5 m Defect located at different angular positions in this section Field emitted Multi-element probe and associated delay (and amplitude) laws Defect response amplitude

20 Defect response Example of validation results Emission: 2 encircling probes (length 20 mm, spacing 50 mm) Axial excitation (6 cycles toneburst at 100 khz) Reception: Small PZT Axisymmetric notch of variable thickness Tang Li-Guo, Mechanism of the excitation of single pure mode L(0,2) and its interaction with the defect in a hollow cylinder, Chinese Physics,

21 Defect response Example of validation results defect height/pipe thickness ratio Very good agreement of the mode conversions 21

22 OUTLINE Functionalities of CIVA GW 10 Mode computation Field computation Defect response Current developments 2D CAD waveguides Arbitrary defects 22

23 Current integration into Civa GW Propagation in arbitrary 2D CAD waveguides Example of mode computation in a rail Width: 152 mm Height: 172 mm Material: steel u x u y u z 23

24 Current integration into Civa GW Arbitrary defects 2D Coupling with a finite element formulation for defect scattering Semi-analytical generation, propagation and detection scattering Transparent boundaries FE Box corrosion pitting 3D Inclusion in a cylindrical rod Crack in the head of a rail Based on an efficient SAFE / FE hybrid model: FE computation of defect scattering hybridised with SAFE computation through specific modal transparent boundaries Baronian et al., J. Comp. Appl. Math.,

25 Conclusion THREE MODULES Mode computation Field computation Defect response (restricted to normal cracks) Available in CIVA GW 10 CURRENT DEVELOPMENTS 2D CAD waveguides Arbitrary defects Anisotropic materials Generation by EMAT (coupling with ET module) a) b) Semi-analytical generation, propagation and detection Generation of SH0 mode with an EMAT c) 1.5 (S.c T ) Transparent boundaries 180 FE Box Slowness curves in composite plate 0 corrosion pitting scattering

26 Thank you for your attention! 26