Experimental evaluation of a morphing leading edge concept

This article presents an experimental evaluation of a morphing leading edge demonstrator by investigating its morphed shape, the level of induced strains in the airfoil skin, the actuation force, and the morphing mechanism’s capability to lock and transfer the applied loads. In addition, a finite element model of the demonstrator is assembled...

Experimental broadband signal reconstruction for plate-like structures

In the Structural Health Monitoring (SHM) field, Acoustic Emissions (AE) is the process by which acoustic signals generated during the formation of damage are captured by sensors, analyzed and used for localization within the structure. In plate like structures, these signals lead to the formation of Lamb Waves (LW), which are broadband in...

Evaluation of mode II fatigue disbonding using Central Cut Plies specimen and distributed strain sensing technology

The lack of a widely-accepted test standard for characterizing the mode II fatigue disbond growth behavior of adhesively bonded interfaces is a challenge to the research community in terms of producing consistent and repeatable results. Typically, researchers apply the End Notch Flexure specimen, which is already used for static delamination...

When Conservation Meets Engineering: Predicting the Damaging Effects of Vibrations on Pastel Paintings

Pastel paintings are one of the most fragile types of objects of art. When handling loan requests, conservators lack scientific data to assess the risk for damage in transport, and thus for making decisions whether they can be transported. A research project was initiated in 2014 to investigate the effect of vibrations on the condition of pastel...

Residual stress effects of a fatigue crack on guided lamb waves

Structural health monitoring has focused on the use of computational models to capture the effect of crack-like discontinuities on the behaviour of acoustic-ultrasonic signals. However, few models have taken into account the effect of geometric complexity in combination with residual stresses generated during the fatigue crack growth (FCG)...

Strain Monitoring using a Rayleigh Backscattering System for a Composite UAV Wing Instrumented with an Embedded Optical Fiber

The primary objective of this research study was to evaluate the capabilities for measuring strain of a composite UAV wing with an embedded optical fiber connected to a Rayleigh backscattering distributed sensing system. This research paper summarizes the manufacturing procedure used during the instrumentation of the composite UAV wing. In...

Sensor Fusion for Shape Sensing: Theory and Numerical Simulation

Computing global strain distributions in complex aerospace and wind energy structures in quasi-real time is an important challenge for the aerospace and wind energy industry. Shape sensing is being considered as a potential means for obtaining global strain fields of complex structures. This is achieved through the use of inverse finite element...

Mechanical behaviour of thermoplastic composites spot-welded and mechanically fastened joints: A preliminary comparison

The in-plane and out-of-plane mechanical behaviour of both ultrasonically spot-welded and mechanically fastened joints was investigated by double-lap shear and pull-through tests, respectively. Spot-welded specimens showed comparable onset failure load and significantly higher joint stiffness compared to mechanical fasteners when carrying shear...

In-Situ Characterization of Isotropic and Transversely Isotropic Elastic Properties Using Ultrasonic Wave Velocities

In this paper, a one-sided, in situ method based on the time of flight measurement of ultrasonic waves was described. The primary application of this technique was to non-destructively measure the stiffness properties of isotropic and transversely isotropic materials. The method consists of generating and receiving quasi-longitudinal and quasi...

Fatigue crack growth in residual stress fields

A statistical model of the motion of pastels under vibration (Poster)

Temperature effects on an acoustic emission based SHM system - Applied to composite materials

This study focuses on understanding the effect of temperature variations and the position of the piezoelectric sensors with respect to fiber orientation angle, as it relates to acoustic emission wave velocity in composite structures. A hybrid panel consisting of Unidirectional Carbon Fiber (UDCF) combined with Unidirectional Glass Fiber (UDGF)...

Fragile! handle with care! The effects of vibrations on pastels in transport (poster)

An investigation on hybrid interface using on-line monitoring experiment and finite element analyses

In this work, the hybrid interface between metal and thermosetting polymer matrix composite was studied via experimental and numerical investigations. Hybrid laminates, whose constituents are aluminum foil, carbon fabric and epoxy matrix, were manufactured using the vacuum assisted resin transfer molding process. Chromic anodization was used to...

Development of Generic Methodology for Designing a Structural Health Monitoring Installation Based on the Acoustic Emission Technique

The Acoustic Emission (AE) technique can be used to perform damage detection and localisation for structural health monitoring purposes. Implementation in aircraft structures however poses a significant challenge as its performance in terms of damage detection and localisation is not well understood when used with complex structural geometries...