The capability of embedded piezoelectric wafer active sensors (PWAS) to perform in-situ ultrasonic nondestructive evaluation (NDE) is explored. Laboratory tests are used to prove that PWAS can satisfactorily perform Lamb wave transmission and reception. Subsequently, pulse-echo method for crack detection in an aircraft panel is illustrated. For large area scanning, a PWAS phased array is used t...

The capabilities of embedded piezoelectric wafer active sensors (PWAS) to perform insitu ultrasonics for active structural health monitoring (SHM) and nondestructive evaluation (NDE) are explored. The paper shows that PWAS, though low-power, lightweight, and small, can successfully perform Lamb wave transmission and reception, pitch-catch and pulse-echo, as well as large area scanning using the...

A probability-based damage detection algorithm has been implemented in order to identify barely visible impact damages in two composite stiffened panels by means of Acousto Ultrasonics (AU). A modification of RAPID (reconstruction algorithm for probabilistic inspection of defects) has been implemented to adapt the algorithm to the current structures and transducer networks. An improvement of 40...

onventional ultrasonic techniques have long been recognized for their usefulness in the nondestructive testing of materials and structures. These techniques, based on launching ultrasonic or high-frequency acoustic waves into a material using a coupled transducer, enable the probing of certain material properties. By inducing surface or bulk waves into a material, several material properties, s...

This paper presents the state of the current activities to develop a high-speed inspection system for evaluating rail defects. Since conventional contact ultrasonic techniques are speed limited, the aim was to build an automatic inspection system, which applies non-contact ultrasonic methods. An automatic Laser Ultrasonic system for Rail Inspection (LURI) has been developed and tested on a rail...

The AC response measurement system is presented. System structure, operation and main units operation are described. The connection setup for a few most common tasks is presented. The obtained results are given. It has been indicated that AC response can be investigated for ultrasonic preamplifier, matching transformer, system filters and ultrasonic transducers. The system is controlled by a pe...