Pedro Poveda Martínez

University of Alicante | UA · Physics, Systems Engineering and Theory of Signal

Abstract: This work presents results allowing an unequivocal correlation of the observations of strong nonlinear elastic features of ultrasonic waves (values of the nonlinearity parameters exceeding the thresholds corresponding to undamaged states), with the critical events of the corrosion-induced surface cracking of reinforced cement-mortar speci...

The dynamic elastic modulus is an important parameter for the study of solid mechanical elements. Even though there exist several well-established standardized methods that allow determining this parameter under a state of simple stresses, some of these may require sophisticated laboratory equipment or involve the use of multiple devices (impulser,...

An important challenge for acoustic engineers in room acoustics design is related to the acoustic performance of multi-purpose auditoriums, which are typically designed to suit several performance requirements. With this intent, the analysis of several scenarios is usually performed individually, and then an acceptable solution, that may be adapted...

In this study, two ultrasonic testing techniques were used and compared to detect corrosion-induced cracking in prismatic mortar samples. Five specimens were prepared and subjected to accelerated corrosion conditions. The different times of exposure allowed to attain unalike damage conditions in every sample. Three out of five samples exhibited a v...

Underwater noise has been identified as a relevant pollutant affecting marine ecosystems in different ways. Despite the numerous studies performed over the last decades regarding the affections of underwater noise to marine life, a lack of knowledge and methodological procedures still exists and results are often tentative or qualitative. A monito...

Many industrial and consumer applications require their components be activated to achieve the desired functionality. In most of the cases, the activation is produced by gear-motors, which adapt speed and torque to the specifications set forth in the design process stage. On the whole, gear-motors consist of a motor as the main energy source provid...

It has been studied the sensitivity of the technique of intermodulation of ultrasonic waves to detect different damage states of concrete due to embedded steel corrosion. Accelerated corrosion tests have been conducted on reinforced cement mortar specimens, while monitoring the appearance and width evolution of visible surface cracks and performing...

One of the most aggressive attacks to which cement-based materials can be exposed is that produced by sulphate. During this attack, expansive products are formed, causing volumetric strains in hardened materials, which brings microcracking and the reduction of their strength and durability. The use of non-destructive techniques for characterizing t...

The aim of this work was to provide further confirmation of the possible use of non-linear ultrasonic techniques for detecting the cracking due to corrosion of steel reinforcements in concrete. To this end accelerated steel corrosion tests have been conducted on model reinforced cement mortar specimens, while monitoring the appearance and width evo...

There are many methods capable of establishing the diagnosis of machinery. The vast majority make use of different condition indicators, extracting information from the vibration signals obtained in the frame. During this work, in addition to using traditional techniques, it was analysed the validity of psychoacoustic metrics as a tool for detectin...

An electrochemical model is presented to calculate the rebar shape time-evolution in reinforced mortar specimens during forced corrosion tests. This provides a more realistic description than the usually used geometric models. The current distribution along the rebar perimeter is calculated by using Finite Element Method (FEM) to solve Laplace equa...

In this work, non-linear ultrasonic wave techniques have been used to detect the onset of micro-cracking due to steel corrosion in model reinforced concrete elements. The specimens were of prismatic shape with a single steel rebar. The corrosion was forced by admixing an appropriate amount of sodium chloride at the moment of preparing the concrete...

Consumers increasingly demand high quality products, forcing manufacturers to a greater effort when designing. During the last years, the noise has become a key factor in valuing a product, so the use of psychoacoustic techniques has been extended considerably. The automotive sector has always taken into consideration the noise when designing vehic...

Este trabajo describe el procedimiento experimental llevado a cabo para estudiar el comportamiento radiante de la superficie de la base de estructuras en forma semilcilindro de 50 cm de diámetro y una superficie lateral de 15 cm de altura cuando son excitados mediante un actuador en el centro de la base. El nivel de vibración ha evaluado mediante a...

Since motorcycles are one of the main sources of noise in urban environments, the use of electric powered two-wheelers may contribute to the improvement of soundscapes in Smart Cities. However, quiet vehicles can lead to an increased risk of accident for pedestrians and other drivers. In order to assess the noise generated by powered two-wheelers a...

Fish anatomical vertical dimensions are extracted from a time-of-flight analysis of fish echo shape using narrow-bandwidth echosounding of swimming individuals. These vertical dimensions fit a Gumbel distribution model and are successfully correlated with fish weight. The proposed method can be used to estimate the mean weight of fish in aquacultur...

Electric and Hybrid Electric vehicles (EV and HEV) seem to be the future of transport in smart cities and the key for the total reduction of noise disturbance and pollution in urban areas. However, several problems have to be solved to guarantee the safety of these types of vehicle. Up to now, the use of HEV has shown the dangers of a “quiet” trans...

In this work, an experiment for early detection of cracks caused by corrosion in engineering structures using nonlinear ultrasonic techniques complemented with conventional techniques is presented. The use of nonlinear effects of ultrasonic has opened a new field in this regard. Higher or lower order harmonics, resonance frequency changes and inter...

Possible drawbacks of microreactors are inefficient reactant mixing and the clogging of microchannels when solid-forming reactions are carried out or solid (catalysts) suspensions are used. Ultrasonic irradiation has been successfully implemented for solving these problems in microreactor configurations ranging from capillaries immersed in ultrason...

The number of offshore wind farms is growing up quickly in the lasts years. Several studies about its environmental acoustic impacts have been developed at the same time the industry expands, most of them related to the high level impulsive noise produced during the pile diving process in construction stage. Nevertheless, the study of the impact of...

Biomass estimation, both weight distribution and fish density, are clue factors for fish farming management. We present the experimental results of the acoustical estimates for both variables in Mediterranean intensive aquaculture floating cages. Sea bass and gilthead sea bream cages have been studied using scientific split beam echosounders with t...

The number of offshore wind farms is growing up quickly in the lasts years. Several studies about its environmental acoustic impacts have been developed at the same time the industry expands, most of them related to the high level impulsive noise produced during the pile diving process associated to the construction stage. Nevertheless, the study o...