Unidad de Posgrado Civil y Mecánica

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    Análisis técnico económico del coeficiente de reducción de respuesta estructural con aplicación y comparación en sistemas aporticados de estructuras metálicas
    (Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-09) Jácome Guanopatín, Ángel Patricio; Cañizares Ortega, Freddy Fernando
    In this degree work, the analysis and calculation of the seismic reduction factor for a structure with special moment frames (PEM or SMF) composed of four different mathematical models where the seismic reduction factor changes with values of R=8, 6, 4, 5 and 3. 5 and 3; performing the dynamic linear structural analysis of the four models, each structure changes according to the demand required by the seismic forces, determining that the lower the value of R the larger sections are required in the structure, in spite of the above, the fundamental vibration period of the structures was maintained for R= 8, 6 and 4. 5, while for the factor R=3 the period is slightly reduced resulting in a stiffer structure, as the seismic response factor is reduced, more robust sections are required to provide more weight to the structure to meet the demand. An economic analysis was performed with the sections obtained, which shows that the lower the R value, the structure requires a higher weight and therefore influences a higher cost, so the structure with the lowest cost is the structure with an R=8. Additionally, a pseudo-static non-linear analysis was determined to determine the structural performance of each of the four models using the ATC-40 and FEMA- 440 methods, highlighting that the models maintain the same architectural and geometric configuration but with different sections in certain elements that required a higher geometry as the R value decreases, after obtaining the results of the static non-linear analysis, the performance point was determined using the ASCE 41-17 and FEMA 440 (2005) methodology, resulting in the R=8, 6, 4. 5 and 3 for 475 years has a performance level in X and Y of immediate occupancy. For the determination of the structural response factor, the methodology proposed by Dr. Aguiar 2006 was followed, which is similar to that of ATC-19 (1995), where the ductility, resistance and redundancy factor is determined, data that are collected from the performance point obtained for the elastic design spectrum with a return period of 475 years, the structural response factors R obtained establish that the average range is between 6 and 7.5, on the other hand the structure that presents greater capacity and performance is the one that was designed with R=4. 5 so having extremely rigid sections does not guarantee stability and ductility in a structure, finally a high level of performance (immediate occupation) and seismic energy dissipation capacity is established in the structure designed with a R=6 where its value is similar and slightly lower than 4.5, so it is concluded that for a structure of special steel composite moment frames a design with a structural response factor equal to 6 should be sought.
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    Comparación de la respuesta sísmica entre pórticos especiales a momento y pórticos arriostrados excéntricamente, en un edificio de acero de 10 pisos, en el cantón Ambato, provincia de Tungurahua
    (Universidad Técnica de Ambato. Facultad de Ingeniería Civil y Mecánica. Maestría en Ingeniería Civil con Mención en Estructuras Metálicas, 2022-09) Aleaga Del Salto, Luis Alfonso; Guevara Robalino, Jorge Javier
    Ecuador is a country of high seismic danger; therefore, the calculation of structures will always be a challenge for engineers since every day new advances in science and technology emerge, making it possible to predict the behavior of a building in extreme events such as earthquakes; in this work the Ceinci-Lab Computer System has been used, which allowed to perform analysis and design of structures step by step obtaining clear and accurate results. The objective of this research is to compare the seismic response between special moment frames and eccentrically braced frames in a 10-story steel building. A simple and regular structural configuration was used to obtain a better seismic performance of all the components of the system. Subsequently, the seismicresistant analysis of the frames was carried out with the different structural configurations proposed in the Ceinci-Lab computer program, using the linear modal spectral and static equivalent analysis for its resolution and complying with the guidelines established in the Ecuadorian construction standard and international codes; finally, it was determined that the building composed of eccentric diagonals had a better seismic response than the one composed of moment resisting frames, obtaining lower displacements and floor drifts; It was also verified that the demand versus capacity of each system is optimal, thus ensuring a strong column - weak beamxvii behavior; additionally, a nonlinear pushover analysis was performed to determine the real maximum resistance of the structure and the performance of all its components; therefore, it is essential to consider the use of bracing in the structural configuration of medium-rise buildings, especially with short link elements, since they act as energy dissipaters, improving the stiffness and global response of the system in severe earthquakes.