Ultrasonics methodology for defect and stress detection of in-serviced T-shaped R-zone components

The T-shaped R-zone component widely exists in aerospace and satellite communication area, such as supporting structure under the wing skin and the mechanical supporting frame of the satellite large load-bearing high-precision test platform, which seriously affects the performance and the safety of the aircraft and the satellite. In this paper, the overall process of ultrasonics methodology of T-shaped R-zone components is proposed, systematically investigated and experimentally verified. The detection of the defect and the stress is respectively realized based on the synthetic aperture total focusing method and the Mohr's stress circle theory with the aid of the linear phased array probe and the longitudinal wave along the stress propagation direction. The theoretical simulations and the experimental measurements both demonstrate the effectiveness of the proposed methodology. The dimensional and the positioning errors are respectively around 0.67 mm and 1.69 mm for the 1 mm × 4 mm crack defect existed in the T-shaped R-zone component. The detecting error of the stress is less than 17.91 MPa in the entire inner of the T-shaped R-zone component, which is applied a pressure in the range of 0-400 MPa.