Estimación de parámetros estructurales en puentes usando la OAPI SAP2000,MATLAB
Fecha
2016-07-05
Autores
Afonso Aspiro, Yunior
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Editor
Universidad Central “Marta Abreu” de Las Villas. Facultad de Construcciones. Departamento de Ingeniería Civil
Resumen
Esta investigación está dirigida a estimar parámetros estructurales (conocido como calibración o actualización) de modelos mecánicos de puentes confeccionados en SAP2000, aprovechando las ventajas de la implementación de los métodos de optimización que posee MATLAB. Para ello se utilizan las posibilidades que brinda la interface OAPI SAP2000 entre SAP2000 y MATLAB. El modelo mecánico elegido es el correspondiente a la superestructura del Puente La Ceniza, km. 9.578, del Ferrocarril Central.
A partir de los parámetros dinámicos obtenidos de un modelo al que se le ha infringido un daño conocido en posiciones arbitrarias, se identifican como los parámetros del comportamiento dinámico "medido", las frecuencias de oscilación natural, las formas modales principales de oscilaciones propias y las curvaturas modales, necesarios para la formulación de la función objetivo del vector compuesto por los residuos de estos tres parámetros modales entre la respuesta modelada y la "medida". Esta función se minimiza empleando técnicas de optimización programadas en MATLAB (Mínimos Cuadrados No Lineal y Algoritmos Genéticos) que al finalizar, proporcionan el modelo estructural calibrado y permiten estimar parámetros estructurales del mismo, como: el Módulo de Elasticidad (E) o los espesores en elementos dañados.
El propósito inmediato una vez obtenido el modelo calibrado del puente objeto de estudio en SAP2000 es facilitar su diagnóstico y evaluación bajo diferentes estados de carga que no pueden ser tomados en cuenta a la hora de realizar los diferentes tipos de ensayos, buscando garantizar que la respuesta del modelo sea aproximadamente igual que la de la estructura real.
This research aims to estimate structural parameters of mechanical models of bridges (known as calibration or model updating) made in SAP2000, taking advantage of the implementation of the optimization methods that has MATLAB. In order to do this, the possibilities offered by the SAP2000 OAPI interface between SAP2000 and MATLAB are used. The chosen mechanical model is the corresponding model to the superstructure of the bridge La Ceniza, km. 9,578, of the Central Railway. The dynamic parameters were obtained from a model that has been inflicted with a known damage at arbitrary positions, the eigenfrequencies, the main mode shapes and modal curvatures are identified as the parameters of the dynamic behavior "measured" necessary for the formulation of the objective function of the vector composed of residues of these three modal parameters between the modeled response and the "measure". This function is minimized using optimization techniques programmed in MATLAB (nonlinear least squares and genetic algorithms) that at the end, provide the structural model calibrated for estimating structural parameters thereof, such as: Modulus of Elasticity (E) or thicknesses damaged elements. The purpose immediately after obtaining the updated bridge model, object of study in SAP2000 is to facilitate the diagnosis and evaluation under different loading conditions that can’t be taken in consideration when performing different types of tests, it seeks to ensure that the model response is approximately equal to the response of the actual structure.
This research aims to estimate structural parameters of mechanical models of bridges (known as calibration or model updating) made in SAP2000, taking advantage of the implementation of the optimization methods that has MATLAB. In order to do this, the possibilities offered by the SAP2000 OAPI interface between SAP2000 and MATLAB are used. The chosen mechanical model is the corresponding model to the superstructure of the bridge La Ceniza, km. 9,578, of the Central Railway. The dynamic parameters were obtained from a model that has been inflicted with a known damage at arbitrary positions, the eigenfrequencies, the main mode shapes and modal curvatures are identified as the parameters of the dynamic behavior "measured" necessary for the formulation of the objective function of the vector composed of residues of these three modal parameters between the modeled response and the "measure". This function is minimized using optimization techniques programmed in MATLAB (nonlinear least squares and genetic algorithms) that at the end, provide the structural model calibrated for estimating structural parameters thereof, such as: Modulus of Elasticity (E) or thicknesses damaged elements. The purpose immediately after obtaining the updated bridge model, object of study in SAP2000 is to facilitate the diagnosis and evaluation under different loading conditions that can’t be taken in consideration when performing different types of tests, it seeks to ensure that the model response is approximately equal to the response of the actual structure.
Descripción
Palabras clave
Parámetros Estructurales en Puentes, OAPI SAP2000 - MATLAB, Puente La Ceniza, km. 9.578, Ferrocarril Central, Parameters, Pons, Railroads