Dynamic Localization and Transient Profile Reconstruction of Internal Defect Based on a Dual-Channel Speckle Interferometer.

The transient response of the internal defect is measured using the dual-channel speckle interferometer based on a high-speed camera and the dual-biprism. The systematic errors caused by the pose of the dual-biprism and the distortion of the lens are considered. An in-depth evaluation of the imaging errors caused by the arbitrary pose of the dual-biprism is performed using the model of virtual points. Internal defect in the structure under multiple loads is precisely localized by calibrating the lens distortion. Temporal speckle pattern interferometry based on the Hilbert transform is used for pixel-by-pixel phase calculation. The transient centroid of the internal defect is localized by first-order derivative, and the profile is reconstructed using out-of-plane displacement. This proposed method provides an accurate visualization of the transient response of internal defects in non-edge clamping.