title: Ultrasonic guided waves in elliptical annular cylinders.
abstract: This paper studies the influence of cross-section ovalness or ellipticity on lower order axisymmetric guided wave modes in thin pipes. The second longitudinal mode L(0,2) and the fundamental torsional mode T(0,1) are studied, as these are of interest to current pipe inspection. The semi-analytical finite element (FE) method is mainly used, with three-dimensional FE simulations for visualization and cross-validation of results. The studies reveal that even a small degree of ovalness can affect mode shapes and velocities. The effect is more pronounced on the L(0,2) mode than on T(0,1) and this may be important for practical inspection applications.
authors.affiliation: Centre for Nondestructive Evaluation, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India prajagopal@iitm.ac.in, roson.pattanayak@gmail.com.
authors.forename: Prabhu
authors.initials: P
authors.lastname: Rajagopal
authors.affiliation: Centre for Nondestructive Evaluation, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India prajagopal@iitm.ac.in, roson.pattanayak@gmail.com.
authors.forename: Roson Kumar
authors.initials: RK
authors.lastname: Pattanayak