Effects of high-amplitude low-frequency structural vibrations and machinery sound waves on ultrasonic guided wave propagation for health monitoring of composite aircraft primary structures

A reliable damage diagnostic by ultrasonic guided wave (GW) based structural health monitoring (SHM) can only be achieved if the physical interactions between wave propagation, the SHM system and environmental factors are fully understood. The purpose of this research was to gain knowledge about the effects of high-amplitude low-frequency...

Systematic multiparameter design methodology for an ultrasonic health monitoring system for full-scale composite aircraft primary structures

The successful utilization of guided wave-based structural health monitoring (SHM) for detailed quantitative diagnostic of damage in composite aircraft primary structures depends on the excitation frequency, geometry, and positioning of the piezoelectric transducers. This study proposes a novel methodology to consistently define those parameters...

Diagnostic of manufacturing defects in ultrasonically welded thermoplastic composite joints using ultrasonic guided waves

This article presents research about the propagation of ultrasonic guided waves in ultrasonically welded thermoplastic composite joints. The goal of the study was to understand the effect of weld manufacturing defects on guided wave transmission across the joint. Triangular energy-directors integrated into the lower composite adherends...

Experimental assessment of the influence of welding process parameters on Lamb wave transmission across ultrasonically welded thermoplastic composite joints

One of the advantages of thermoplastic composites relative to their thermoset counterparts is the possibility of assembling components through welding. Ultrasonic welding in particular is very promising for industrialization. However, uncertainty in the fatigue and fracture behaviour of composites is still an obstacle to the full utilisation...

Full-scale testing of an ultrasonic guided wave based structural health monitoring system for a thermoplastic composite aircraft primary structure

This paper describes the test campaign of an ultrasonic guided wave (GW) based structural health monitoring system (SHM) deployed on a full-scale stiffened panel of a thermoplastic composite horizontal stabilizer torsion box. The diagnostic capabilities of the SHM system were successfully evaluated by testing barely-visible impact damage of...

Reliability Analysis of an Ultrasonic Guided Wave Based Structural Health Monitoring System for a Carbon Fibre Reinforced Thermoplastic Torsion-box

Certification is the key step towards the implementation of structural health monitoring (SHM) as part of condition based maintenance programmes of aircraft fleets. That can only be accomplished by demonstration of system performance in multiple scenarios and in a statistically relevant way. This paper describes a fully computational approach...

Experimental characterisation of Lamb wave propagation through thermoplastic composite ultrasonic welds

Ultrasonic welding is a very promising technique for joining thermoplastic composite (TpC) components in aircraft primary structures [1, 2]. The potential introduction of new lightweight structures in civil aviation has been driving the change towards condition-based maintenance (CBM) as an alternative to the regular inspection interval approach...