Structural Health Monitoring through Surface Acoustic Wave Inspection on Capillaries Integrated with Additive Manufacturing Techniques. Vrije Universiteit Brussel
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Piezoelectric materials are able to convert an applied electrical signal into mechanical strain and stress. By using an electrical signal with a certain frequency, it is possible to generate an acoustic signal with the same frequency. Specially designed devices are able to generate the acoustic signals along the surface of a substrate. The generated Surface Acoustic Waves (SAWs) propagate on top of this piezoelectric substrate. Devices using ...
Nowadays, many buildings are equipped with ETFE membranes and cushions. ETFE is a fluoropolymer that can be extruded to form membranes. These membranes are commonly used to construct visually transparent building claddings. Their use for covering large indoor spaces is relatively common. The design benefits include design flexibility, designing with less support material due to the reduced weight and an increased lifespan of the cladding ...
Acoustics, functioning either positively or negatively, is considered an important aspect of products in automotive, aerospace, smart electronics, home appliances, etc. With the rapid development of computer-aided engineering (CAE), acoustics simulations have become essential for product design, analysis, and optimization. A robust and efficient acoustics simulation software can significantly reduce the time-to-market thus improving the ...
In this dissertation, SAM is utilized at GHz frequencies, namely the GHz-SAM, to explore its potential in detecting μm and sub-μm sized defects for various state-of-the-art FA challenges.
Firstly, artefacts hindering proper analysis of the composed acoustic images were analyzed, their root cause was identified, and means to reduce their effects on the GHz-SAM images were proposed. For an in-depth understanding of the GHz-SAM images, the ...
Detecting the initiation and growth of damage and the identification of the dominant damage mechanism within a structural component is of paramount engineering importance as it allows to effectively (re-) design or reinforce the structure to withstand the observed failure mode. The behavior of masonry under compression is particularly complex as its structural response is related to the relative mechanical properties of the bricks/blocks, the ...
The global concern in building acoustics is to achieve the necessary sound insulation and to create pleasant and supportive room acoustics conditions. In recent years, special interest for the performances at low frequencies (below 200 Hz) emerged. This raises major questions: how to master the sound insulation in this frequency range and how to influence the low-frequent listening experience? Both questions relate to the proliferation of ...
The solar atmosphere is in a dynamic state and ubiquitous waves can be observed in all layers. At the same time, above the photosphere, the temperature increases in the chromosphere and corona with increasing distance from the solar surface. It is yet not clear which non-thermal process supplies the upper layers with sufficient energy to maintain their temperature. This is termed the coronal heating problem. The ubiquitous waves in the solar ...