Edwin Forero

Bio: Edwin Forero is an academic researcher from Universidad Santo Tomás. The author has contributed to research in topics: Structural health monitoring & Fault detection and isolation. The author has an hindex of 3, co-authored 13 publications receiving 32 citations. Previous affiliations of Edwin Forero include United States Tennis Association.

Development of a System for Detecting Weld Failures

Abstract: Considering the possibility that from the area of electronics can be provided feasible solutions in the field of non-destructive testing, this chapter present a prototype and methodology that allows energize an ultrasound transducer. This system is used to evaluate for detecting weld failures at the junctions of metallic parts. Subsequently, in order to validate the design quality of that source, a computer system that allows control of a card developed ultrasound. Finally, it is implemented the ultrasonic imaging by time of flight diffraction technique, in order to obtain an objective comparison methodology to both systems.

A sensor fault detection methodology applied to piezoelectric active systems in structural health monitoring applications

Abstract: Damage detection is the basis of the damage identification task in Structural Health Monitoring. A good damage detection process can ensure the adequate work of a SHM System because allows to know early information about the presence of a damage in a structure under evaluation. However this process is based on the premise that all sensors are well installed and they are working properly, however, it is not true all the time. Problems such as debonding, cuts and the use of the sensors under different environmental and operational conditions result in changes in the vibrational response and a bad functioning in the SHM system. As a contribution to evaluate the state of the sensors in a SHM system, this paper describes a methodology for sensor fault detection in a piezoelectric active system. The methodology involves the use of PCA for multivariate analysis and some damage indices as pattern recognition technique and is tested in a blade from a wind turbine where different scenarios are evaluated including sensor cuts and debonding.

Diseño y construcción de un sistema para examen no destructivo de fallas y defectos en metales utilizando señales ultrasónicas

Abstract: En el presente articulo se describe el diseno y construccion de un sistema electronico para examen no destructivo con ultrasonido (ENDU), que es una de las tecnicas mas utilizadas para evaluar sin deteriorar piezas metalmecanicas en diversas areas de la industria. Las tecnicas de evaluacion que se presentan en este trabajo son difraccion de tiempo de vuelo (TOFD) y pulso-eco, para cuya prueba se incorporaron deliberadamente defectos en uniones metalicas soldadas (probetas). El sistema implementado consta de palpadores angulares dispuestos de acuerdo con la tecnica que se utilizo en cada caso, un pulsador que alimenta adecuadamente a los palpadores, los metodos de adquisicion y procesamiento digital de la informacion. En el documento se incluyen graficos A-Scan y D-Scan que ilustran un caso tipico de analisis como ejemplo. Finalmente, se muestra que el sistema desarrollado demostro ser efectivo comparado con examenes ejecutados con un equipo comercial de la misma naturaleza y con otra tecnica de inspeccion como la radiografica.

Estimation of energy efficiency in solar photovoltaic panels considering environmental variables

Abstract: The present work has been made to find out the relationship between the efficiency of two types of photovoltaics panels, monocrystalline and polycrystalline, and the weather variation in the city of Bogota-Colombia. The power generated of two photovoltaic panels, one monocrystalline and one polycrystalline, were collected for one month, 24 hours in condition of variant weather. At the same time, it was implemented a weather station that registered the variations of climatic variables like wind speed, temperature, humidity, irradiance and rainfall, to relate them with the generated power of each photovoltaic panel. Once with this information collected it a study was made with all the correlated variables through of the statistic tool PCA (Principals Components Analysis) where it was seen the impact of each climatic variable over the generated power in both panels and therefore its impact over the efficiency.

NDT Non-Destructive Test for Quality Evaluation of Concrete specimens by Ultrasonic Pulse Velocity measurement

Abstract: Knowing the quality of concrete is very important, because this type of material is part of the design and implementation of most structures such as bridges, buildings, tunnels, among others, in this investigation non-destructive tests were carried out on test specimens of using ultrasound, which were designed and developed in the concrete laboratory at Santo Tomas University in Bogota DC taking into account for its preparation a dosage of the estimated concrete mixture in order to obtain specimens with a compressive strength of 3500psi, 2500psi and 1500psi, in such a way, the specimens were allowed to cure for a period of 28 days, ensuring that they achieved their maximum compression strengthAs mentioned above, non-destructive ultrasound tests were applied in order to determine the quality of the manufactured concrete specimens, thus, an ultrasound system is proposed that makes it possible to pass an acoustic wave through a concrete specimen, this was proposed with the purpose of measuring the velocity with which the wave passes in the volume of this material, known as the ultrasonic pulse velocity Therefore, the respective velocities for each of the concrete specimens were measured, thus finding a relationship between the ultrasonic pulse velocity and the compressive strength, which finally makes possible the evaluation of the manufactured concrete specimens

A Sensor Data Fusion System Based on k-Nearest Neighbor Pattern Classification for Structural Health Monitoring Applications

Abstract: Civil and military structures are susceptible and vulnerable to damage due to the environmental and operational conditions. Therefore, the implementation of technology to provide robust solutions in damage identification (by using signals acquired directly from the structure) is a requirement to reduce operational and maintenance costs. In this sense, the use of sensors permanently attached to the structures has demonstrated a great versatility and benefit since the inspection system can be automated. This automation is carried out with signal processing tasks with the aim of a pattern recognition analysis. This work presents the detailed description of a structural health monitoring (SHM) system based on the use of a piezoelectric (PZT) active system. The SHM system includes: (i) the use of a piezoelectric sensor network to excite the structure and collect the measured dynamic response, in several actuation phases; (ii) data organization; (iii) advanced signal processing techniques to define the feature vectors; and finally; (iv) the nearest neighbor algorithm as a machine learning approach to classify different kinds of damage. A description of the experimental setup, the experimental validation and a discussion of the results from two different structures are included and analyzed.

Recent Advancements in Non-Destructive Testing Techniques for Structural Health Monitoring

Abstract: Structural health monitoring (SHM) is an important aspect of the assessment of various structures and infrastructure, which involves inspection, monitoring, and maintenance to support economics, quality of life and sustainability in civil engineering. Currently, research has been conducted in order to develop non-destructive techniques for SHM to extend the lifespan of monitored structures. This paper will review and summarize the recent advancements in non-destructive testing techniques, namely, sweep frequency approach, ground penetrating radar, infrared technique, fiber optics sensors, camera-based methods, laser scanner techniques, acoustic emission and ultrasonic techniques. Although some of the techniques are widely and successfully utilized in civil engineering, there are still challenges that researchers are addressing. One of the common challenges within the techniques is interpretation, analysis and automation of obtained data, which requires highly skilled and specialized experts. Therefore, researchers are investigating and applying artificial intelligence, namely machine learning algorithms to address the challenges. In addition, researchers have combined multiple techniques in order to improve accuracy and acquire additional parameters to enhance the measurement processes. This study mainly focuses on the scope and recent advancements of the Non-destructive Testing (NDT) application for SHM of concrete, masonry, timber and steel structures.

Distributed Piezoelectric Sensor System for Damage Identification in Structures Subjected to Temperature Changes.

Abstract: Structural health monitoring (SHM) is a very important area in a wide spectrum of fields and engineering applications. With an SHM system, it is possible to reduce the number of non-necessary inspection tasks, the associated risk and the maintenance cost in a wide range of structures during their lifetime. One of the problems in the detection and classification of damage are the constant changes in the operational and environmental conditions. Small changes of these conditions can be considered by the SHM system as damage even though the structure is healthy. Several applications for monitoring of structures have been developed and reported in the literature, and some of them include temperature compensation techniques. In real applications, however, digital processing technologies have proven their value by: (i) offering a very interesting way to acquire information from the structures under test; (ii) applying methodologies to provide a robust analysis; and (iii) performing a damage identification with a practical useful accuracy. This work shows the implementation of an SHM system based on the use of piezoelectric (PZT) sensors for inspecting a structure subjected to temperature changes. The methodology includes the use of multivariate analysis, sensor data fusion and machine learning approaches. The methodology is tested and evaluated with aluminum and composite structures that are subjected to temperature variations. Results show that damage can be detected and classified in all of the cases in spite of the temperature changes.

Methodology for risk assessment and costs associated with risk occurrence in e-government projects

Abstract: The main purpose of this chapter is to emphasize the problem of e-government projects risks and to introduce a methodology for risk assessment and calculation of costs associated with risk occurrence in e-government projects based on Bayesian networks. The proposed methodology presents a new approach to the assessment of risks and costs related to e-government project risks. As such, it facilitates the holistic decision making procedure for project managers. The application of Bayesian networks in the context of risks and risk related costs reduces the level of uncertainty in e-government projects and provides a graphical structure of risks and corresponding costs. Finally, the sensitivity analysis has also been integrated into the methodology and its results can have a significant impact on the overall project management quality.

Landslides : a guide to researching landslide phenomena and processes

Abstract: Landslide research is an interdisciplinary field that primarily encompasses scientists from geomorphology, engineering geology, and geotechnical engineering in collaboration with researchers from such fields as geodesy, hydrogeology, geophysics, and many others. This chapter is intended as a resource for researchers interested in landslide engineering and landslide science to acquire a summarized review of research subjects and the state-of- the-art literature. A wide range of landslide topics are presented in the following sections, that is, landslide mapping, landslide investigation, landslide monitoring, landslide hazard and risk assessment, and landslide stabilization and remediation measures. The results of landslide studies have practical applications to society via the avoidance, prevention, and mitigation of landslide hazards and risks. Landslide avoidance and prevention are the primary interests for land-use policies based on landslide mapping, followed by the prediction of landslide processes and their consequences. Landslide mitigation includes the development of engineering technologies for landslide investigation, monitoring, and remediation.