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.

Damage detection in quasi-isotropic composite bends using ultrasonic feature guided waves

“…Ultrasonic guided wave testing can be an effective alternative since it potentially allows for rapid screening of large areas with a fixed transducer position and remote inspection of structures with difficult access. In recent years, one particular branch of guided waves confined to local structural variation -feature guided waves (FGW) have received much attention and been discussed in the literature extensively [5,6,7,8,9,10,11,12,13,14,15]. Guided waves not only exists in the regular waveguides (e.g.…”

Remote monitoring of bond line defects between a composite panel and a stiffener using distributed piezoelectric sensors

“…In recent years, one particular branch of guided waves confined to local structural variation, i.e. feature guided waves (FGW), have attracted much interest and been extensively reported in the literature [36][37][38][39][40]. The FGW modes are capable of strongly focusing the wave energy in the structural feature to propagate long distances and are therefore attractive for quick inspection of long-range features.…”

Feature-guided wave-based health monitoring of bent plates using fiber Bragg gratings

“…Recently, the above challenge has been addressed using ultrasonic guided waves confined to locally extended features such as welds, bends, thinning or thickening regions (Fan and Lowe, 2009, 2012; Pattanayak et al, 2015; Rajagopal and Pattanayak, 2015; Ramdhas et al, 2013). Such confined elastic waves are now more commonly referred to as ‘feature-guided waves’ (FGW) (Lawrie and Kaplunov, 2012).…”