Unidad de Posgrado Civil y Mecánica
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Item Análisis de los elementos estructurales utilizados en el diseño de una edificación de dos pisos con un sistema estructural liviano (Steel Framing)(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-09) Alarcón Cárdenas, Fredy Israel; Sánchez Sánchez, Xavier RolandoThe development of civil construction leads to industrialized and modern construction systems. One of these is Steel Framing (SF), cold-formed galvanized steel profiles enclosed by cement board, wood or gypsum board panels. In the Ecuadorian environment there is concern about the safety of its structural components. The seismic demand to which the country is subjected requires the construction sector to innovate construction systems, especially for the residential building sector, in order to carry out construction processes with less environmental impact and better seismic resistant behavior that guarantees the safety of the occupants. The materials used in the SF construction system lack reliability in the local market, since they are in a discrete commercialization state due to their low demand and limited consumer scope, which is mainly composed of professionals dedicated to real estate projects. In this study, the structural design of a 2-story residential building was carried out, verifying the mechanical properties of SF by testing its main structural elements. The samples were extracted from profiles available in the market and were analyzed through mechanical tests in several laboratories in the country. During the tests, tensilexvi behavior, metallography, hardness, chemical composition, electron microscopy and coating thickness measurements were evaluated. The results showed that the structural elements that make up the SF system meet the mechanical requirements requested by the structural design standards and its application is feasible in the proposed building, taking into account the good quality of the material used in the manufacture of the profiles used in this construction system. In addition to the results obtained numerically, it is important to emphasize the advantages of the SF, in terms of weight of its elements (light structures), speed of execution and good environmental practices in the construction process.Item Determinación del proceso tecnológico para la fabricación de fachaletas de PVC como material opcional en la construcción de viviendas(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Mecánica Mención Manufactura, 2021-06) Solís Santamaria, Tannia Magally; Carrillo Rosero, Carlos MauricioThis project deals with the manufacture of cladding by injection molding of PVC polymer as an alternative material for the construction industry, where the analysis and design of the cladding mold are carried out using CAD/CAM software programs. The use of CAD/CAM tools allows reducing both, production time and cost. As this process occurs through injection molding, custom products can be manufactured meeting the needs of various sectors. Through the determination to depend upon the technological process for the manufacture of cladding, tests are carried out to validate the mechanical properties of cladding through compression, impact, and flammability tests along with UV ray experiments, thickness, production, and commercial cost, which are parameters to determine the quality of the product. To simplify the manufacturing process, a technological report of this study was conducted through the description of adequate parameters for its correct production. The results were favorable as 896 cladding molds, with a thickness of 2 mm, a net weight of 25 grams, and a selling price of 3.73 U.S. dollars per square meter, were produced. Therefore, cladding commercial cost, as well as weight, are significantly lowered concerning what it would represent within the construction industry.Item Optimización de las propiedades mecánicas a fractura para juntas soldadas a tope bajo proceso SMAW (AWS D1.1) utilizadas en la fabricación de estructuras metálicas en la compañía SEMADIJE LTDA(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Mecánica Mención Manufactura, 2021-06) Reyes Pérez, Diego Fernando; Paredes Salinas, Juan GilbertoThe present development work is focused on the optimization of the mechanical properties to fracture for butt welded joints under SMAW process. For this purpose, a combination analysis of the most influential variables in the welding process was carried out and its mechanical properties were tested by tensile, crack propagation and impact tests. The base material used for this research was ASTM A572 grade 50 steel, with E-6010, E-6011 and E-7018 filler materials, using different percentages of the latter for each combination. Regarding the welded joints, the SMAW welding process was used, which complies with the requirements of the AWS D1.1 code, and which is widely used in the manufacture of metallic structures. From the aforementioned tests, evaluations were obtained, which allow to statistically analyze each one of them, which allows to obtain the optimum combination with respect to their resistance to fracture, both individually and globally. After the respective analyses, it can be seen that the combination that presents an improvement in the mechanical properties to fracture is the one that corresponds to the use of the E-7018 electrode with a type of X-shaped joint.Item Estudio de la influencia del proceso de soldadura del acero HSLA ASTM A500 GR C utilizado en carrocerías de buses en sus propiedades mecánicas(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Mecánica Mención Diseño, 2020-09) Carrasco Carrasco, Luis Roberto; López Villacís, Gonzalo EduardoThis research is intended to define the influence of the heat contributed by the welding process of the bus bodywork on the properties of the material and its capacity of resistance to impact, and for this purpose it began with the testing of ASTM A500 steel without welding. Then, the test was carried out with the E6011 electrode central weld and with the ER70S-6 electrode, measuring the deformation with an initial length of 100mm. It can be effectively verified that the welding process does affect the properties of the material. The most affected property was the modulus of elasticity with a change that exceeded 80 percent, which means that the welding process modified the material making it more rigid and brittle due to the change in temperature and the cooling rate. The yield stress of the material in the welded area decreased to 10 percent, which also reduces the safety factor in this area. Following this, the impact simulation of the front of the bus bodywork was modeled and performed by using the results of the tests in the welding area. The simulation results allowed to identify the areas where the greatest stresses occur, these were located in the area of the frontal collision near the welded joints, but not on the welds. The stress in these areas exceeded the maximum yield stress, but the percentage deformations were less than the tests without breaking the structure.Item Análisis de la influencia de las pruebas tecnológicas sobre las propiedades mecánicas de compuestos de resina polimérica reforzado con fibras naturales del Ecuador bajo norma ASTM(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Mecánica Mención Diseño, 2019) Salán Guevara, Luis Geovanny; Analuiza Maiza, Oscar IvánThis document responds to an investigative work, against the lack of knowledge of the degree of degradation of composites in the open air, for this purpose the study of the influence of UV radiation and humidity, considered as technological tests, on the mechanical properties of tensile and flexion in two types of composite materials, one with a matrix of polyester resin and reinforcement of cabuya fiber and the other with the same matrix of the previous one with banana fiber reinforcement, under ASTM regulations. In order to determine the percentage of humidity and UV affectation in the aforementioned composite materials, by comparing their properties and determining which one offers better anti-degrading benefits to technological tests, tensile and flexural tests were carried out in the pre and post phases exposure to them. From the experimental treatment of the data obtained, conclusions are established that determine that the composite with better characteristics to resist technological tests is one that uses banana reinforcement. Subsequently, it was validated its use within the automotive industry - body supported by the analysis of finite elements performed by the specialized software intermediary, determining that its ideal application is for internal cover for bus roofs.Item Análisis de la aleación mecánica de aluminio 1060 con porcentajes controlados en peso de zinc y su incidencia en la resistencia última a la tensión, dureza e impacto(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Mecánica Mención Diseño, 2019) Pineda Silva, Giovanny Vinicio; López Villacís, Gonzalo EduardoThe research project begins due to the need to have technically documented information related to powder metallurgy within the scope of mechanical alloy, manufacturing process that is entering into the National Industry, due to the advantages it presents with respect to traditional processes; being the most representative, a more exact control of the limits of the composition, optimization of raw material and is a process susceptible to automation with good surface finish for serial production of mechanical components. The experimental process of the mechanical alloy begins with the obtaining of mechanical powder of the base elements: Aluminum 1060 with particle size 30 micrometers and alloying: Zinc with particle size between 45−63 micrometers through the use of ball mill and a screening control; mixing process based on the percentages in weight defined for the subsequent compaction and sintering of the test pieces for the correct development of the tests. The study of tensile strength, hardness and impact was developed though the control of variables of percentage by weight of alloying element: 0.5 – 1.0 y 1.5 percentage Zinc, and sintering temperature: 462 celcius degrees y 594 celsius degrees ; the best results were obtained in the case of a study developed with 1 percentage Zinc and a temperature of 594 celsius degrees, where the hardness and tensile strength were increased by 69 percentage and 12.29 percentage respectively in relation to the base element; while the impact resistance as a function of the energy absorbed decreases by 39.40 percentage in the best case 1 percentage Zinc and 462 celsius degrees; in addition, the controlled variables are correlated with each other and directly affect the properties under study according to the statistical analysis developed by Fisher’s test.Item Estudio de las propiedades mecánicas de los fluidos magnetoreológicos MRF-140CG para determinar su resistencia al flujo bajo la aplicación de campos magnéticos de intensidad variable(Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Diseño Mecánico, 2017) Arteaga López, Oscar Bladimir; Espín Lagos, Segundo ManuelThe research assesses the extent to which the properties of MRF-140CG magnetorheological fluids are altered as the intensity of the magnetic field increases, in order to predict their behavior in devices that use these materials, thus contributing to the design of intelligent mechanical devices, each more sophisticated, reliable and efficient, according to each need. To measure the properties of the MRF-140CG fluid, a Anton Paar Physica MCR-501 rotational rheometer equipped with a MRD- 70 / 1Text magneto-rheological cell was used. From the results of the investigation, it was determined that Bingham's plastic model predicts the dynamic behavior of the MRF-140CG fluid with greater precision compared with others, with an average error rate close to 4%, demonstrating that in the absence of magnetic field the viscosity of the fluid decreases as the temperature increases, whilst under the action of a magnetic field, the resistance to the flow of the fluid increases with the intensity of the field, reaching a maximum value of 42.014 kPa at 800 mT.Item Efecto del tiempo en el proceso de homogenizado en la extrubilidad del aluminio 6063 en la empresa Cedal(Universidad Técnica de Ambato, Facultad de Ingeniería Civil y Mecánica. Maestría en Diseño Mecánico, 2017) Reinoso Peñaherrera, Héctor Raúl; Espín Lagos, Segundo ManuelThe research carried out in the CEDAL company analyzes the changes in the mechanical and microstructural properties of the 6063 alloy and relates them to the defects present in aluminum extrusion in different batches that have been subjected to different homogenization times (4, 5 and 6 hours of support at 565oC). The report compares the values of mechanical strength, elongation, hardness, grain size and microstructural changes between the specimens before being homogenized and those specimens that have been homogenized for 4, 5 and 6 hours. In addition, given the traceability, it is possible to identify the defects present after the extrusion process and to associate them with the homogenization time, so that keeping the aluminum ingots in the homogenization oven for 5 hours at a temperature of 565oC represents the most appropriate option so that the alloy presents the best characteristics in the final product and as raw material to the extrusion process. A proposal is presented as the procedure that will guarantee the verification, control and validation of the raw material, as well as to guarantee its traceability and to associate it with the defects that occur in the extrusion process.Item Estudio de la aleación inteligente con memoria de forma Cu-Zn para determinar su aplicación industrial(Universidad Técnica de Ambato, Facultad de Ingeniería Civil y Mecánica. Maestría en Diseño Mecánico, 2017) Criollo Camacho, Marcia Ximena; Espín Lagos, Segundo ManuelIn the present research work, the study of the intelligent alloy with Cu-Zn shape-memory was developed to determine its industrial application, five tests of casting with different quantities of alloying elements were conducted, mainly varying the quantities of Zn, until achieving a percentage of 59.32% Cu and 40.08% Zn, obtaining with this composition that the alloy behaves as an intelligent material with shape-memory, which returns to its predetermined form in the presence of an external stimulus, in this case the reaction to the presence of heat, it has characteristics such as superelasticity and thermal memory, the mechanical properties were determined based on ASTM standards, such as metallographic, traction, impact and hardness tests of the material obtained. In function of the properties achieved, an industrial application is given, proposing to use as a switch or actuator, which closes or opens a circuit when applying heat.Item Estudio del tratamiento térmico post soldadura del acero inoxidable martensítico ASTM A743 grado CA6-NM y su incidencia en las propiedades mecánicas del material aplicado a la recuperación de rodetes hidráulicos(Universidad Técnica de Ambato, Facultad de Ingeniería Civil y Mecánica. Maestría en Diseño Mecánico, 2017) Auz Mogrovejo, Juan José; Vaca Ortega, Wilson HenryASTM A743 grade CA6-NM Martensitic Stainless Steel is used in the manufacture of runners and other components of hydraulic turbines to provide a good combination between mechanical properties and resistance to cavitation and corrosion. Due to its low carbon content it has good weldability; however, it is necessary to perform post-weld heat treatment to alleviate stress and to fine tune the microstructure and mechanical properties in order to recover characteristics similar to those of the original material. Through the present work the effect of the heat treatment of ASTM A743 grade CA6-NM steel was studied after applying deposits of multi-step welding of accumulation type or restoration the thickness of the base metal using a GMAW robotized process with ER410NiMo electrodes on slotted coupons which reproduce part of the worn surface of a hydraulic runner. The welded coupons were subjected to different heat treatments in order to compare the mechanical properties of the weld material without heat treatment and with post-weld tempering at a temperature of 600 °C during two different holding times, one and two hours; in addition, this process was performed for one, two and three cycles of recovery by welding plus heat treatment. Eight cases of study were considered, including the original base material, the weld without heat treatment and six cases of post-welding tempering, which were subjected to tests of tension, impact, hardness and metallography to characterize and establish the variation of the mechanical properties. From this analysis it was determined that the post-weld heat treatment applied allows to improve the properties that are affected by the welding process. The best combination of mechanical properties was obtained for tempering at 600 °C during two hours in the first recovery. It was verified that even in the third recovery the properties of the material are within the parameters required by the standard ASTM A743. Finally, a procedure is proposed for the recovery of Francis hydraulic runners as an alternative for the maintenance of turbines at a lower cost.