Saeed Izadpanah - Petroleum University of Technology, Abadan, Iran
Gholam Reza Rashed - Petroleum University of Technology, Ahvaz, Iran
Sina Sodagar - University of Toronto, Toronto, Canada

Nowadays, using the relatively long tubular structures, such as transmission pipeline and drilling strings, are common in many industries such as oil, petrochemicals and power plants. In regards to the sensitivity of these structures, they need proper inspection method for ensuring the reliability and lack of defects. But Inspection of these structures with ordinary non destructive test are expensive, difficult and in some cases impossible due to excessive length ,inaccessibility to the entire structures and also dependency on exact evaluation of defects. In light of above mentioned difficulties, using guided waves for inspection of structure have been considered by many researchers due to possibility of using various waves with different properties. Therefore, this article outlines principles, characteristic, advantageous, disadvantageous and limitation of non destructive method for inspection of tubular structures such as pipes by means of guided waves. Also propagation of the waves in the longitudinal direction of cylindrical waveguide will be investigated.

Ultrasonic, Guided waves , tubular structure , dispersion curve