Investigation on stretchable eddy current array sensor for crack inspection in steel curved structures of offshore platforms

Eddy current array sensors are widely used for the detection of planar defects; however, their applicability to curved structures has remained relatively underexplored. To address the need for crack detection on jacket platforms in harsh marine environments, this paper presents the optimized design and performance evaluation of a flexible eddy current array sensor. The proposed sensor incorporates a PDMS-based flexible protective layer that provides waterproofing, UV resistance, salt-spray corrosion resistance, and tensile durability. Finite element simulations were conducted to systematically investigate the influence of key structural parameters on detection sensitivity, and the optimal design parameters were determined accordingly. The results demonstrate that the optimized sensor can detect cracks as small as 1 mm in length, 0.2 mm in width, and 1 mm in depth on curved surfaces. This study offers a sensing solution of practical engineering value for the long-term and efficient structural health monitoring of curved-surface cracks on jacket platforms.