Fig.1

Laser-EMAT conversion mechanism

Fig.2

Resonant components corresponding to different mesh sizes R

Fig.3

Resonant frequency f7 corresponding to different mesh sizes R

Fig.4

Ultrasonic wave signals corresponding to different computation time steps

Fig.5

Resonance frequencies corresponding to different computation time steps

Fig.6

Schematic diagram of design parameters and finite element model of laser-EMAT

Table 1

Design parameters of finite element model for laser-EMAT

Fig.7

Schematic diagram of stepped sample for laser electromagnetic ultrasonic transverse wave resonance thickness measurement

Fig.8

Longitudinal and shear wave signals corresponding to aluminum alloy 5083 specimen with thickness of 3.0 mm

Fig.9

Longitudinal and shear wave velocity for aluminum alloy 5083， stainless steel 304， and nickel-based alloy GH4169

Fig.10

A-scan signals and spectral components of 5083 aluminum alloy samples with different thicknesses

Fig.11

Average frequency differences corresponding to aluminum alloy 5073， stainless steel 304， and GH4169 with different plate thicknesses f¯

Table 2

Thickness measurement data from a simulation of laser-EMAT shear wave resonance

Fig.12

Changes in A-scan signal， spectral signal， and resonance point frequency f3， f4， f5， f6， and f7 of aluminum alloy 5083 sample with a thickness of 3.0 mm at different laser spot diameters

Fig.13

Spectral composition of aluminum alloy 5083 sample with thickness of 3.0 mm at different EMAT coil outer diameters

Fig.14

Corresponding f4， f5， f6， f7， f8 of aluminum alloy 5083 sample with thickness of 3.0 mm at different EMAT coil outer diameters

Fig.15

Spectral composition of aluminum alloy 5083 sample with thickness of 3mm corresponding to different EMAT coil wire diameters

Fig.16

Corresponding f4， f5， f6， f7， f8 of aluminum alloy 5083 sample with thickness of 3.0 mm at different EMAT coil diameters

Fig.17

Normalized amplitudes of partial resonant frequency points corresponding to different lift-offs for aluminum alloy 5083 specimen with thickness of 3.0 mm

Fig.18

Point difference values of adjacent resonant frequencies for aluminum alloy 5083 specimen with thickness of 3.0 mm at different lift-offs

Fig.19

Schematic diagram of laser-EMAT shear wave resonance thickness measurement system

Fig.20

Laser-EMAT shear wave resonance thickness measurement system

Fig.21

Experimental results of aluminum alloy 5083 specimen with thickness of 3.0 mm at different laser spot diameters

Fig.22

Experimental results of aluminum alloy 5083 samples with thickness of 3.0 mm and different EMAT coil outer diameters

Fig.23

Experimental results of aluminum alloy 5083 samples with thickness of 3.0 mm and different EMAT coil diameters

Fig.24

Experimental results of aluminum alloy 5083 specimens with a thickness of 3.0 mm at different EMAT lift off times

Fig.25

Aluminum alloy 5083， stainless steel 304， and GH4169 step specimens

Fig.26

Experimental A-scan signals of samples with different thicknesses

Fig.27

Experimental spectrum composition of 5083 aluminum alloy samples with different thicknesses

Fig.28

Experimental spectrum composition of 304 stainless steel samples with different thicknesses

Fig.29

Experimental spectrum composition of nickel-based alloy GH4169 samples with different thicknesses

Table 3

Measured thickness and deviation of laser-EMAT shear wave resonance

Fig.30

High-temperature laser-EMAT shear wave resonance thickness measurement device

Fig.31

High temperature experiment A scan signal of 3.0 mm thick sample

Fig.32

High temperature experimental spectrum composition of 3.0 mm thick samples