Cracks progression and detection in composite pipes based on Eddy current techniques and inverse problems using a fast algorithm search optimizer

Determining crack dimensions is essential for assessing fracture behaviour and crack propagation in structures subjected to fatigue, static or dynamic loading. Crack depth is particularly difficult to evaluate using conventional techniques and is important to the structural integrity of critical components such as pipelines. This study presents a three-dimensional Eddy current non-destructive testing approach for characterising surface-breaking cracks in composite pipes. A finite-element model is used to examine how crack length, width and depth affect coil impedance amplitude, resistance and reactance in CFRP pipes. A deterministic inverse algorithm is coupled to the numerical forward model to estimate crack depth from resistance. The numerical results show monotonic relationships between the simulated impedance components and crack dimensions, and the worked inversion example converges to the prescribed numerical target within ten iterations. These findings support further development of the method for automated inspection; experimental validation and timing benchmarks remain future work.