This paper presents a study of angle shear connectors with two types of orientations. Shear connectors are used to transfer shear forces through the steel–concrete. In Ecuador constructors make buildings using different types of shear connectors and most of them have not been studied. Indeed, using angles is cheaper than studs and channels. In this study, fourteen composite specimens containing steel angle shear connectors were prepared to determine the full capacity of those angles. The angles were set in 45° and 90° orientation. Monotonic, cyclic load, and push out loading tests were applied, and shear strength, ductility, failure modes and stiffness were discussed. Comparing the two groups it was concluded that Group A (45°) presents less scatter than Group B (90°). In both groups, first cracks appeared when samples reach 50 % of the expected failure load and became greater and longer about 80 %, and all samples experienced failure of the connector. Group A specimens had a better behavior in terms of the ultimate shear capacity and satisfied ductility criteria given by Eurocode. Group B specimens presented similar results to Group A, but with a larger scatter. Finally, shear capacities from tests are compared with some code formulas, using an analogy, and it is found that codes give slightly lower results.

Durante años se ha venido construyendo losas de hormigón sobre vigas de acero, sin embargo, el no considerar la trasmisión de esfuerzos de corte entre ellas, ocasiona que los elementos trabajen por separado. Para asegurar la transmisión de esfuerzos, la carga debe transmitirse mediante conectores mecánicos. En la construcción comúnmente se utilizan pernos stud, perfiles angulares y tornillos como conectores, aunque no todos se encuentren normados. El presente trabajo analiza el comportamiento de conectores de corte tipo ángulo, cuando están localizados de diferente manera a la expuesta en códigos de diseño. Para ello, se consideraron conectores de corte tipo ángulo, colocados de manera perpendicular respecto a la cara del patín de la viga de acero, analizando dos tipos de posiciones (45 y 90° referente al eje longitudinal del patín). Para comprobar cuál tiene un comportamiento y resistencia adecuada, se realizaron ensayos push-out, con un total de 6 probetas por posición. Las curvas fuerza vs. deslizamiento obtenidas del conector a 45°, presentaron un comportamiento más homogéneo en todos los parámetros analizados, en comparación con las curvas obtenidas para el conector a 90°. Su óptimo rendimiento hace que el conector a 45° sea el más adecuado para implementación.

The significance of electric vehicles is progressively escalating, underscoring the criticality of technologies underpinning the functionality of their propulsion systems. This particular case study delves into the simulation of field-oriented control, coupled with field weakening, aimed at regulating a salient-pole permanent-magnet synchronous motor (PMSM). This approach involves the utilization of two cascaded loops for current and voltage, each employing PI controllers. The fine-tuning of these controllers’ parameters hinges on the motor characteristics, as well as the desired response bandwidth.

En la investigación que aquí se presenta se evaluó el comportamiento estructural de dos viviendas adosadas construidas de manera informal, las cuales mostraban diversos problemas estructurales como: golpeteo, columnas cortas y discontinuidad de columnas; se determinaron las propiedades mecánicas de los materiales y de suelo por medio de ensayos in situ y de laboratorio. Posteriormente, se realizó el análisis mediante modelos matemáticos, mismos que se calibraron con periodos tomados de vibraciones ambientales. En esta etapa se encontró que las estructuras no exhibían un comportamiento adecuado para resistir fuerzas gravitacionales y sísmicas, por lo que se propuso el reforzamiento de ambas estructuras por medio del enchape de mampostería, además se planteó unir ambas viviendas a nivel de losa con placas metálicas para eliminar el problema del golpeteo. Finalmente, se evaluó el reforzamiento propuesto y se evidenció que el enchape rigidizó las estructuras permitiendo que estas cumplan con los requisitos establecidos por la normativa vigente a bajo costo

This study introduces a general procedure to analyze the structural vulnerability of large areas applied to an unusual problem. Thus, the vulnerability of a whole neighborhood to two simultaneous extreme events has been analyzed. For this task, the Multi-Criteria Decision Making analysis based on experts' judgment has been an excellent option to be used, but it has some drawbacks. For example, it is difficult to make a judgment for every house, especially when there are uncommon problems. Then, freeware has been used for Machine Learning (ML) methods in order to induce every building's performance. Moreover, in order to have a more accurate result in ML, case-based decision theory has been studied to help experts by creating structural analyses’ examples of vulnerability levels. Finally, the Fuzzy Logic Method has been employed to convert the criteria results into smoother numerical levels and to include the uncertainty of experts' judgments. Therefore, an algorithm that includes the interaction with the experts has been developed. Here, the justification for using all those procedures is shown, and it is also demonstrated that they can be applied with freeware. Copyright © 2021 Praise Worthy Prize - All rights reserved.