Corrosion Detection in Pipelines Based on Measurement of Natural Frequencies

Natural frequency of structure mainly depends on mass and stiffness. Stiffness is bound to change after structural damage. Hence, natural frequency starts to decline. This study presents a new method to determine the location and degree of the corrosion damage by measuring the natural frequencies of the damaged pipeline. With this method, only measurement of the first and second natural frequencies of damaged pipeline is required. The formulation is based on Rayleigh's Law to determine a relationship between the degree of damage and damage location. The formulation is validated by comparing against beam and solid fi nite element models.