Local vibration mode pairs for damage identification in axisymmetric tubular structures

Tubular structures are widely used in infrastructure, especially for pipes and marine installations. Corrosion is a key damage type these structures, if undetected may cause structural deficiency or even collapse. This paper investigates the effects of localised corrosion on vibration properties axisymmetric tubular proposes novel baseline-free identification method to overcome fact that difference between undamaged damaged usually small contaminated by noise. The proposed vibration-based exploits phenomenon repeated mode pairs which peculiar with non-axisymmetric damage. Unlike intact it found each locally structure comprises two components: active passive. component sensitive local can be infer existence while passive retentive pipe's properties. Therefore, pipe’s pair (LVMP) predict its baseline (undamaged) modal properties, this research was achieved within margin ±2%, whereas confirms existence. work also establishes criteria validation LVMPs through experimental tests involving various scenarios ranging from longitudinal strips through-thickness pits. Based obtained results, linked corrosion-like underpinning new detection approach.