Fique is a fiber of South American origin that has adequate properties to be used as reinforcement in composite materials, recently there have been various research for the development of composite materials with this fiber type. This article compiles different studies into composite materials reinforced with fique fiber. Initially discussed the issues related to the properties and treatments most commonly used to fiber to improve their quality and adhesion, then the types of matrix and the main manufacturing techniques that have been used for the manufacture of composites reinforced with fique fiber are described, followed by the different tests and characterization tests that have been applied to them to know their main properties and finally, their applications and the use of micromechanical models to describe them.

Abstract:This project aims to determine the coefficient of dynamic friction between micrometric size coatings of alumina and metallic materials (Steel and aluminium); the methodology used to achieve the proposed objective consisted of 4 phases, in the first one was developed a procedure that allowed, from a Pin on Disk machine built based on the specifications given by the ASTM G99-05 standard (Standard test method for wear tests with a Pin on Disk machine), to determine the coefficient of dynamic friction between two materials in contact; subsequently the methodology was verified through tests between steel-steel and steelaluminium, due to these values are widely reported in the literature; as a third step, deposits of alumina particles of micrometric size were made on a steel substrate through thermal spraying by flame; finally, the tests were carried out between pins of steel of aluminium and alumina coating to determine the coefficients of dynamic friction between these two surfaces. The results of the project allowed to verify that the developed methodology is valid to obtain coefficients of dynamic friction between surfaces in contact since the percentages of error were of 3.5% and 2.1% for steel-steel and aluminium-steel, respectively; additionally, it was found that the coefficient of friction between steel-alumina coatings is 0.36 and aluminium-alumina coating is 0.25.

The main objective of this article is to evaluate the wind resource in the city of Floridablanca, Colombia. In Colombia, the supply of electrical energy comes mainly from hydroelectric mega-power stations, presenting generation problems in times of drought. The wind resource is an adequate alternative to diversify the electricity supply in the country. To analyze the characteristics of the wind, recorded measurements were carried out, every 15 minutes at a height of 30 m, throughout the year 2016, at a meteorological station located in Floridablanca, Colombia. In this study we present a statistical analysis of the wind characteristics in Floridablanca, Colombia, we applied a Weibull distribution of two parameters to model the wind speed and thus determine the wind potential. The average annual speed was 0.72 m/s with a standard deviation of 0.61 m/s. The monthly Weibull scale parameter varied from 0.52 m/s to 0.91 m/s, the monthly parameter varied from 0.98 to 1.37. The highest power density observed was 0.35 w/m 2 in the months of February and August, the monthly average power density was 0.23 w/m 2 which indicates a very poor wind potential considering that they are considered good wind potentials greater than 500 w/m 2. This study contributes to evaluate the wind potential of Floridablanca, Colombia, and can be used, methodologically, to quantify the wind potential with possibilities of generating electric power in any part of the country.

El presente estudio describe la fabricación de un dron cuadricóptero elaborado en material compuesto reforzado con fibra de fique, el cual fue caracterizado morfológica, mecánica y dinámicamente. El marco del cuadricóptero se fabricó utilizando 6 capas de fique (35.4% del peso) y una matriz de poliéster. La electrónica y el sistema de control se basaron en el uso de la arquitectura Arduino Nano. El análisis morfológico por microscopia electrónica mostró delaminación de la matriz y una adhesión media resina-fibra. La caracterización mecánica se realizó en dirección longitudinal y transversal obteniéndose un esfuerzo máximo de tensión de 32.20 MPa y 25.72 MPa respectivamente. La mayor amplitud de vibración se da a la frecuencia de operación de los motores, siendo esta 89 Hz. En conclusión, el dron puede entrar en resonancia ya que para llegar a la frecuencia de operación de los motores se debe excitar la primera frecuencia natural del marco.

The use of natural fibers as reinforcement for composite materials is on the rise due to the need to reduce environmental damage and manufacture sustainable products. One of the fibers used for this purpose is fique fiber. This article describes the manufacture of a student chair with fique fiber-reinforced composite material. To choose the amount of reinforcement to be used in the elaboration of the chair, the mechanical characterization of several composites with different percentages of the fiber was carried out, where it was found that both the flexural and tensile properties increased with a higher insertion of fique. The selected material was analyzed morphologically with optical microscopy, finding that there was good adhesion between the fiber and the matrix. A simulation with finite elements showed that the chair would resist a load of 100 kg. The student chair was manufactured using the Hand Lay Up technique with material composed of fique fiber and polyester resin.

En este trabajo se presenta un procedimiento general para la simulación del comportamiento del flujo en los intercambiadores de tubos y aletas con una gran flexibilidad en el manejo de la información. Este procedimiento está basado en el uso de Programación Orientada a Objetos y específicamente al uso de C++, esto debido a todas las ventajas de este tipo de programación. La entrada de datos se lleva a cabo por medio de archivos, de forma que programas de terceros puedan generar la configuración del intercambiador y permitir calcular el intercambiador en forma paramétrica. Los resultados para el análisis se presentan en tres formatos diferentes: valores separados por comas (CSV), texto plano estructurado y autodocumentado (XML) y un formato para la visualización gráfica de resultados (VTK).

Gracias a sus propiedades, el uso de materiales compuestos en aplicaciones industriales se ha incrementado en las últimas décadas especialmente los que cuentan con refuerzos de fibras naturales debido a su menor impacto ambiental, sin embargo, uno de los grandes desafíos que presentan este tipo de material es darles forma por medio de corte ya que se puede comprometer su integridad superficial. En el presente trabajo se realiza un análisis morfológico a material compuesto con fibra de fique evaluando la afectación superficial por corte realizado con herramienta convencional, laser y chorro de agua. El material se fabricó con seis capas de fibra de fique y resina poliéster. El estudio morfológico se llevó a cabo por medio de microscopia electrónica de barrido donde se evidenciaron altos defectos con la herramienta convencional, una afectación a la matriz en el corte con láser y un bajo impacto superficial utilizando el chorro de agua.

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