Show simple item record

dc.contributor.advisorSuárez, Luis E.
dc.contributor.authorCruz-Gutiérrez, Ernesto G.
dc.date.accessioned2018-11-21T10:35:05Z
dc.date.available2018-11-21T10:35:05Z
dc.date.issued2016
dc.identifier.urihttps://hdl.handle.net/20.500.11801/1472
dc.description.abstractThe equivalent linear method is widely used in Geotechnical Earthquake Engineering to calculate the accelerations at the surface of soil deposits subject to earthquakes of moderate intensity. The method approximately takes into account the non-linear behavior of soils by using equivalent shear moduli and damping ratios that are function of effective shear strains. A series of linear analysis are performed each time using equivalent soil properties until their values at two consecutive steps are approximately equal. The effective strain is defined by reducing the peak strain retrieved from the time response. The reduction factor, usually 0.65, accounts for the fact that the peak strain only occurs at a single instant of time. This thesis investigates the application of this technique to calculate the seismic response of reinforced concrete buildings with moderate non-linear behavior. The method is tested using a 3-D finite element model of a building created in the program ANSYS. Non-linear constitutive relations in the form of stress vs. strain are used to calculate the full non-linear response and also to define the equivalent modulus of elasticity and damping ratio by means of the Masing’s rule. It was found that a key parameter affecting the accuracy of the results is the reduction factor. Considering a number of seismic records with different frequency contents an optimal reduction factor was defined that is a function of six parameters related to the intensity of the earthquake. The accuracy of the results obtained with the equivalent linear method depends on the response of interest sought (displacement, shear, moment, acceleration) but it proved to be quite acceptable for all the cases considered. The floor response spectra for the building with non-linear behavior were also obtained and they compare very well with those computed with the exact non-linear analysis.en_US
dc.description.abstractEl método lineal equivalente es altamente utilizado en Ingeniería Sísmica Geotécnica para calcular las aceleraciones en la superficie de depósitos de suelos sometidos a un sismo de intensidad moderada. El método toma en cuenta en forma aproximada el comportamiento no lineal de los suelos mediante el uso de un módulo de corte y razón de amortiguamiento equivalentes. Se realizan una serie de análisis lineales en el tiempo usando en cada etapa propiedades lineales equivalentes obtenidas de curvas que definen estas propiedades en función de la deformación específica. De la respuesta en el tiempo se extrae el valor máximo el cual se reduce por factor de 0.65 para tener en cuenta que el valor pico no se repite en el tiempo. En este trabajo se aplica esta técnica para calcular la respuesta sísmica de edificios de hormigón armado con un comportamiento no lineal moderado. La respuesta exacta del edificio se calcula usando un modelo con elementos finitos tridimensionales en el programa ANSYS. Usando curvas del módulo de elasticidad y de razón de amortiguamiento equivalentes en función de la deformación unitaria se definen modelos lineales equivalentes. Un parámetro clave que afecta la precisión de los resultados es el factor de reducción. Considerando una serie de registros sísmicos con distintos contenidos de frecuencia se obtiene un factor de reducción óptimo que se define en función de seis parámetros relacionados a una medida de intensidad de los sismos. La precisión de los resultados obtenidos con el método lineal equivalente depende de la respuesta de interés (desplazamientos, cortantes, momentos, aceleraciones) pero los errores se mantienen dentro de márgenes aceptables. También se obtuvieron también los espectros de respuesta de piso para el edificio con comportamiento no-linear y se compararon con los calculados con el análisis no linear exacto lo cual dio buenos resultados.en_US
dc.description.sponsorshipThis work was performed under award NRC-HQ-12-G-38-0018 from the US Nuclear Regulatory Commission. The statements, findings, conclusions, and recommendations are those of the authors and do not necessarily reflect the view of the US Nuclear Regulatory Commission.en_US
dc.language.isoenen_US
dc.subjectseismic responseen_US
dc.subject.lcshBuildings, Reinforced concrete -- Earthquake effectsen_US
dc.subject.lcshEarthquake resistant designen_US
dc.subject.lcshFinite element methoden_US
dc.subject.lcshSeismic reflection method -- Deconvolutionen_US
dc.subject.lcshANSYSen_US
dc.titleSeismic response of inelastic concrete structures using the equivalent linear methoden_US
dc.typeThesisen_US
dc.rights.licenseAll rights reserveden_US
dc.rights.holder(c) 2016 Ernesto Gabriel Cruz Gutiérrezen_US
dc.contributor.committeeMontejo Valencia, Luis A.
dc.contributor.committeeLópez Rodríguez, Ricardo R.
dc.contributor.representativeLópez Venegas, Alberto M.
thesis.degree.levelM.S.en_US
thesis.degree.disciplineCivil Engineeringen_US
dc.contributor.collegeCollege of Engineeringen_US
dc.contributor.departmentDepartment of Civil Engineeringen_US
dc.description.graduationSemesterFallen_US
dc.description.graduationYear2016en_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

  • Theses & Dissertations
    Items included under this collection are theses, dissertations, and project reports submitted as a requirement for completing a graduate degree at UPR-Mayagüez.

Show simple item record

All rights reserved
Except where otherwise noted, this item's license is described as All Rights Reserved