Laser shock deformation measurement based on multi-channel dynamic shearography

This paper proposes a real-time, high-precision material deformation monitoring method based on spatial-carrier dual-directional shearography for investigating the dynamic deformation behavior of materials during laser shock peening (LSP). By optimizing the optical system design, a tri-aperture misaligned configuration was introduced at the Fourier plane of the transform lens. This enables synchronous measurement along orthogonal shear directions and decoupled control of constant spatial-carrier frequencies. By configuring the aperture parameters, distinct spatial carrier frequencies were introduced into the speckle patterns, ensuring complete spectral separation of the interferograms in the frequency domain. The shearographic phase maps were subsequently obtained by applying the windowed inverse Fourier transform, thereby facilitating real-time strain measurement. This approach provides real-time, high-precision dynamic monitoring throughout the LSP process. The performance of the spatial-carrier dual-directional shearography system is described through theoretical derivation, optomechanical design, and experimentation.