This paper deals with the study of damage produced during freeze-thaw (F-T) cycles using two non-destructive measurement approaches—the first approach devoted to continuous monitoring using embedded sensors during the cycles, and the second one, performing ultrasonic imaging before and after the cycles. Both methodologies have been tested in two different types of concrete specimens, with and without air-entraining agents. Using the first measurement approach, the size and distribution of pores were estimated using a thermoporometrical model and continuous measurements of temperature and ultrasonic velocity along cycles. These estimates have been compared with the results obtained using mercury porosimetry testing. In the second approach, the damage due to F-T cycles has been evaluated by automated ultrasonic transmission and pulse-echo inspections made before and after the cycles. With these inspections the variations in the dimensions, velocity and attenuation caused by the accelerated F-T cycles were determined.

This article aims to highlight the importance of utilizing flow visualization techniques in the preliminary analysis of streamlined and bluff bodies, especially the potential use of visualization with ink in a water channel as a tool for a preliminary approach during fluid mechanics analysis. According to this, the study compares the results obtained using a classical flow visualization technique, ink injection in water, with those obtained through the employment of a laser-based measurement and visualization technique, called PIV, in a low-speed wind tunnel. The article briefly presents both techniques and highlights the importance of flow visualization in the analysis of aerodynamic bodies. This study focuses on flow over NACA airfoils at extremely low Reynolds numbers, which is of great interest for application in extraterrestrial atmospheres, such as on Mars. After obtaining images of the flow streamlines over the NACA 0018 airfoil, the results of both techniques were compared. The results indicated that there was good agreement between the visualization with the water channel and the PIV results, suggesting that the results obtained in the water channel represented a scientifically valid approximation and an essential complement to computational models that require experimental validation.

The aim of this paper is to analyse the influence of mortar bed joint thickness on the structural behaviour of brick-masonry specimens under compressive stress. Moreover, the progressive cracking of the material was studied during the loading process. Nine walls and nine columns were tested, combining three mortar bed joint thicknesses. Simultaneously, ultrasound, extensometer and Schmidt hammer measurements were recorded. The obtained results show that the thinner the mortar bed joint (5mm), the greater the breaking load (20.5N/mm2) and ultrasonic pulse speed. In addition, ultrasound evaluation shows good agreement with the extensometer measurements and allows accurate detection of the inner material failure.

This paper shows a series of tools that help in the research of morphing micro air vehicles (MAVs). These tools are aimed at generating parametric CAD models of wings in a few seconds that can be used in aerodynamic studies, either via CFD directly using the model obtained or via wind tunnel through rapid prototyping with 3D printers. It also facilitates the analysis of morphing wings by allowing for the continuous parametric deformation of the airfoils and the wing geometry. In addition, one of the tools greatly simplifies the purely experimental design of this type of vehicle, allowing the transfer of experimental measurements to the computer, generating virtual models with the same deformation as the physical model. This software has two fundamental parts. The first one is the parameterization of the airfoils, for which the CST (Class-Shape Transformation) method will be used. CST coefficients can be modified according to the actuator variable that changes the wing geometry. The second part is the generation of a three-dimensional parametric model of the wing. We used OpenCASCADE technology in its Python version called PythonOCC, which enables the generation of geometries with good surface quality for typical and non-standard wing shapes. Finally, the use of this software for the study of a morphing aircraft will be shown, as well as improvements that could be incorporated in the future to increase its capabilities for the design and analysis of MAVs.