Ultrasonic guided waves inspection using Lamb waves is suitable for damage detection in metallic structures. This paper will present experimental results obtained using guided Lamb waves to detect flaws in aluminum specimens with design features applicable to space applications. Two aluminum panels were fabricated from a variable-thickness aluminum top plate, with two bolted I-beams edge stiffe...

The feeder pipe in the pressurized heavy water reactor (PHWR) is exposed to a possible leakage during operation. Because of the geometrical complexity of the pipe and its inaccessibility due to a high radiation environment, it is difficult to examine the defect by the conventional ultrasonic method. The guided ultrasonic inspection was chosen for the inspection of the pipe. The torsional mode h...

Ultrasonic fiber optic sensors (UFOS) based on Mach-Zehnder (M-Z) interferometer is proposed to detect guided waves propagating in the pipe, which is common structural component in aerospace, mechanical or civil structures. The sensitivity of UFOS depends on the long sensing distance, while winding around the circumferential direction of the pipe provides arbitrary sensing length as well as sma...

Ultrasonic wedges which can propagate one longitudinal L and two orthogonally polarized shear S waves are presented. In order to use this wedge to generate and received guided plate acoustic waves along a metal plate at high temperatures brass which has a slow L and S wave velocities was chosen. Mode conversion method was used to convert L to S waves in the wedge. The mode conversion efficiency...

The novel ultrasonic NDT technique based on application of long range guided waves is proposed for detection of defects in a storage tank floor. The technique needs access only to the outer edge of the tank floor and do not require emptying and cleaning inside of the tank. The technique has been developed on the basis of the Lamb wave transmission tomography. The propagation of the guided waves...

Probing material degradation and properties change to anticipate stages of damage can be achieved using advanced in-situ and hybrid non-contact remote ultrasonic sensing including laser generation and air-coupled detection arrangements. The sensing technology is based on application of guided waves such as plate (Lamb waves) or surface waves (Rayleigh waves) for direct material interrogation th...

The modeling of the interaction between piezoelectric wafer active sensors (PWAS) and structural waves and vibration is addressed. Three main issues are discussed: (a) modeling of pitch-catch ultrasonic waves between a PWAS transmitter and a PWAS receiver by comparison between exact Lamb wave solutions and various finite element method (FEM) results; (b) analytical modeling of the power and ene...