Paulo Amado-Mendes

Numerical Analysis of Acoustic Barriers with a Diffusive Surface Using a 2.5D Boundary Element Model

Acoustic barriers are a well-known environmental noise mitigation solution, which is widely used nowadays. In this work, it is expected to contribute to the body of knowledge regarding the physical and technical behavior of those barriers by developing and implementing a set of models that allow an accurate analysis of noise barriers with new configuration types. A 2.5D boundary-only numerical model is developed and implemented, and computational analyses are performed in order to compare different surface profiles of the acoustic barriers. The particular case in which two acoustic barriers are used, one at each side of the road, is addressed.

An Efficient MFS Formulation for the Analysis of Acoustic Scattering by Periodic Structures

The acoustic behavior of periodic structures has been a subject of intense study in recent years. From the computational point of view, these devices have mostly been analyzed using strategies such as the multiple scattering theory (MST) or numerical methods such as the finite element method (FEM). Some recent works propose the use of boundary methods, such as the method of fundamental solutions (MFS) or the boundary element method (BEM). However, the geometry and the large number of scatterers of these devices can lead to very large memory requirements and CPU times, which, particularly in the case of 3D problems, can be prohibitive. Here, a new numerical approach based on a frequency domain MFS formulation is proposed for 3D problems, allowing the analysis of very large problems. In this approach, the periodic character of the devices is used to define a matrix with a block structure, in which repeated blocks are only calculated once. In addition, an adaptive-cross-approximation (ACA) approach is incorp...

A Bio-inspired Framework for Highly Efficient Structural Health Monitoring and Vibration Analysis

Civil engineering structures are continuously exposed to the risk of damage whether due to ageing effects, excessive live loads or extreme events, such as earthquakes, blasts and cyclones. If not readily identified, damage will inevitably compromise the structural integrity, leading the system to stop operating and undergo in-depth interventions. The economic and social impacts associated with such an adverse condition can be significant, therefore effective methods able to early identify structural vulnerabilities are needed for these systems to keep meeting the required life-safety standards and avoid the impairment of their normal function. In this context, vibration-based analysis approaches play a leading role as they allow to detect structural faults which lie beneath the surface of the structure by identifying and quantifying anomalous changes in the system’s inherent vibration characteristics. However, although the considerable degree of maturity attained within the fields of experimental vibration analysis (EVA) and structural health monitoring (SHM), several technical issues still need to be addressed in order to ensure the successful implementation of these powerful tools for damage identification purposes.