scholarly journals Structural Behavior of the General Archive of the Nation (AGN) Building, Mexico

2018 ◽  
Vol 3 (3) ◽  
pp. 39
Author(s):  
Marcos Chávez ◽  
Fernando Peña ◽  
Claudia Cruz ◽  
Gustavo Monroy
Keyword(s):  
Dynamic Properties ◽  
Ambient Vibration ◽  
Structural Behavior ◽  
High Plasticity ◽  
Fundamental Vibration ◽  
Vibration Period ◽  
Ambient Vibration Tests ◽  
Smeared Crack ◽  
The Government ◽  
Vibration Tests

This article presents a study on the structural behavior of the Government Building that is part of the old Lecumberri Palace and which currently houses the Mexican General Archive of the Nation. This building was inaugurated in 1900 and closed in 1976, after serving as a prison for 76 years. It was reopened in 1982 after it had undergone several remodeling works. The construction is made of brick masonry with lime mortar. It is supported by a deposit of overly compressible high-plasticity clays. The main problems of this building are the appearance of cracks in both interior and exterior walls, and moisture in the ground floor, caused by differential settlements. The study entailed a geometric and a damage survey as well as ambient vibration tests in order to determine the dynamic properties of the construction. The data obtained was used for the making of a model that, using the finite element method, was analyzed under different load conditions. This study has focused on the overall response with the assumption of smeared crack damage. According to the results, the building’s safety was deemed as acceptable. It has the capability to withstand seismic actions as established by the Mexican Building Code due to the high density of its walls and the resulting stiffness, which infer that the fundamental vibration period of the building would be distant from the predominant vibration period of the soil. This highlights the idea that the building’s critical condition is constituted by the differential settlements, which cause damage in the construction.

scholarly journals Multi-scale model updating of a timber footbridge using experimental vibration data

2017 ◽  
Vol 34 (3) ◽  
pp. 754-780 ◽  
Author(s):  
Rafael Castro-Triguero ◽  
Enrique Garcia-Macias ◽  
Erick Saavedra Flores ◽  
M.I. Friswell ◽  
Rafael Gallego
Keyword(s):  
Structural Model ◽  
Model Updating ◽  
Ambient Vibration ◽  
Scale Model ◽  
Structural Behavior ◽  
Modal Parameters ◽  
Content Type ◽  
Multi Scale ◽  
Ambient Vibration Tests ◽  
Vibration Tests

Purpose The purpose of this paper is to capture the actual structural behavior of the longest timber footbridge in Spain by means of a multi-scale model updating approach in conjunction with ambient vibration tests. Design/methodology/approach In a first stage, a numerical pre-test analysis of the full bridge is performed, using standard beam-type finite elements with isotropic material properties. This approach offers a first structural model in which optimal sensor placement (OSP) methodologies are applied to improve the system identification process. In particular, the effective independence (EFI) method is used to determine the optimal locations of a set of sensors. Ambient vibration tests are conducted to determine experimentally the modal characteristics of the structure. The identified modal parameters are compared with those values obtained from this preliminary model. To improve the accuracy of the numerical predictions, the material response is modeled by means of a homogenization-based multi-scale computational approach. In a second stage, the structure is modeled by means of three-dimensional solid elements with the above material definition, capturing realistically the full orthotropic mechanical properties of wood. A genetic algorithm (GA) technique is adopted to calibrate the micromechanical parameters which are either not well-known or susceptible to considerable variations when measured experimentally. Findings An overall good agreement is found between the results of the updated numerical simulations and the corresponding experimental measurements. The longitudinal and transverse Young's moduli, sliding and rolling shear moduli, density and natural frequencies are computed by the present approach. The obtained results reveal the potential predictive capabilities of the present GA/multi-scale/experimental approach to capture accurately the actual behavior of complex materials and structures. Originality/value The uniqueness and importance of this structure leads to an intensive study of its structural behavior. Ambient vibration tests are carried out under environmental excitation. Extraction of modal parameters is obtained from output-only experimental data. The EFI methodology is applied for the OSP on a large-scale structure. Information coming from several length scales, from sub-micrometer dimensions to macroscopic scales, is included in the material definition. The strong differences found between the stiffness along the longitudinal and transverse directions of wood lumbers are incorporated in the structural model. A multi-scale model updating approach is carried out by means of a GA technique to calibrate the micromechanical parameters which are either not well-known or susceptible to considerable variations when measured experimentally.

scholarly journals Ambient Vibration Tests of an Arch Dam with Different Reservoir Water Levels: Experimental Results and Comparison with Finite Element Modelling

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Sergio Vincenzo Calcina ◽  
Laura Eltrudis ◽  
Luca Piroddi ◽  
Gaetano Ranieri
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Water Levels ◽  
Arch Dam ◽  
Experimental Results ◽  
Ambient Vibration ◽  
Reservoir Water ◽  
Ambient Vibration Tests ◽  
Vibration Properties ◽  
Vibration Tests

This paper deals with the ambient vibration tests performed in an arch dam in two different working conditions in order to assess the effect produced by two different reservoir water levels on the structural vibration properties. The study consists of an experimental part and a numerical part. The experimental tests were carried out in two different periods of the year, at the beginning of autumn (October 2012) and at the end of winter (March 2013), respectively. The measurements were performed using a fast technique based on asynchronous records of microtremor time-series. In-contact single-station measurements were done by means of one single high resolution triaxial tromometer and two low-frequency seismometers, placed in different points of the structure. The Standard Spectral Ratio method has been used to evaluate the natural frequencies of vibration of the structure. A 3D finite element model of the arch dam-reservoir-foundation system has been developed to verify analytically determined vibration properties, such as natural frequencies and mode shapes, and their changes linked to water level with the experimental results.

Ambient Vibration Tests of Suspension Bridge

1978 ◽  
Vol 104 (5) ◽  
pp. 983-999
Author(s):  
Ahmed M. Abdel-Ghaffar ◽  
George W. Housner
Keyword(s):  
Suspension Bridge ◽  
Ambient Vibration ◽  
Ambient Vibration Tests ◽  
Vibration Tests

scholarly journals Damping estimation using free decays and ambient vibration tests

2010 ◽  
Vol 24 (5) ◽  
pp. 1274-1290 ◽  
Author(s):  
Filipe Magalhães ◽  
Álvaro Cunha ◽  
Elsa Caetano ◽  
Rune Brincker
Keyword(s):  
Ambient Vibration ◽  
Ambient Vibration Tests ◽  
Vibration Tests ◽  
Damping Estimation
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